What to Bring
Clothing
Fleece Jacket/Pullover - bring 1 lightweight long-sleeved fleece. In the early mornings it is chilly, and on one day during my trip it was downright cold. You can spend a lot or very litte (mine cost under 20 euros from Tchibo) as today there are amazingly light weight functional fabrics. I ended up using my fleece often as extra padding under the should straps of my backpack.
Gloves - a pair of lightweight hiking gloves would be highly advisable, especially if you take my advice and bring two walking poles. There was a day on the Camino that the weather turned suddenly very cold, near freezing with wind, and my hands became so cold that I could not push the button on my camera because they were so numb. Odlo makes a pair of lightweight gloves (look under accessories). A lightweight pair with open fingertips might also be advantageous.
Hat - I had only one day of rain the entire month I was underway, so protection from the sun is a critical factor. I recommend a hat that has a rather wide brim, but not too wide as a floppy gardening hat will probably fall prey at some point to gusts of wind. The brim should encompass the circumference of the hat so as to protect your neck. Remember you are walking ever westward and the sun will be on your neck all the way to Santiago. I bought a Columbia hat that had a mesh net in the hood of the hat. I not only appreciated the ventilation, but when I would take my siesta in the albergues it doubled as a way to darken bright rooms by pulling it over my eyes, while at the same time offering me the ability to keep an eye on albergue events with incognito peeks through the mesh. Doubles as good backup sun shading for the eyes if you should lose your sunglasses, which I did.
Hiking Boots - I recommend you buy sturdy, high quality, ankle-covering hiking boots. You will be walking on quite rocky and unstable ground many times. You may need to walk through some muddy areas, and possibly low water, weather depending. I saw many pilgrims wearing everyday tennis shoes, such as Keds, sandals(!), or other types of everyday shoes. These were the pilgrims that tended to have massive blisters, serious foot problems, acute aches and pains, foot infections(!), and injuries due to this underestimation. Buy the best quality you can afford and make sure you walk in them more than just a few times before you go. You don't need to scale Mt. Everest beforehand, but two weeks of taking frequent 1 or 2 hours walks in your new shoes would be wise.
Lanyard - It gives you one less thing to worry about when you take your sunglasses off while walking, or relaxing. Just don't do what I did, I hung my beloved borrowed sunglasses by the lanyard on a bunk bed post and one sleepy early morning, I left them there.
Rain Jacket - if you are going in the spring/summer months your rain jacket is going to be the only jacket you will need to have along. It should be lightweight and have a hood. I looked at very expensive jackets that I could hardly believe would protect me from rain, but today's sophisticated functional fabrics are pretty amazing. I had an inexpensive jacket that was not so sophisticated, but that functioned just fine.
Rain Pants - I must have been very lucky because I only had to put on the rain pants once and only for about an hour. There are pilgrims who opt for the rain poncho instead. I decided the pants were more practical because ponchos don't protect from blowing rain and wind, whereas the rain pants could also double as an extra layer should the temperature drop significantly.
Rain Cover for Backpack - very often when you buy your backpack the rain cover will come with it. It worked well and luckily I only had to use it once for a brief time.
Shirts - quantity: 2, no more than 3. Avoid cotton, as it is quite heavy when wet (you will be sweating) and does not dry as fast as many synthetic fabrics available today. I had two shirts made by Odlo, one short sleeved and one sleeveless. They were actually designed as underwear shirts, but I wore them as outer wear. Odlo products are antibacterial to prevent odor. The underwear is graded according to temperature, which is really smart. I also had a feather light, cheap "microfaser" short sleeved shirt, and a Columbia short sleeved hiking shirt. I really didn't need four. The Odlo sleeveless shirt became a favorite shirt to sleep in because it was the coolest.
Shoes(non-hiking) - you will want a pair of shoes either sandals or other leisure type, to wear in the alberque, or to walk to the supermercado, or in and around the area (Because what does every pilgrim love to do after a day of 25-35 kilometers of walking and a little siesta? Walk some more, of course!). I originally had three pairs of shoes: my hiking boots, a lightweight pair of leisure shoes, and my .50 euro cent flip flops for showering with. I ended up sending the leisure shoes ahead to Santiago in one of two parcels. I found that I did not want anything on my feet after I had taken my boots off. I also found that airing out my feet, and especially not having anything on the heel area (not to mention toes), was the way to go. That said, while the flip flops held up fine and worked out ok, there are better choices. Chaco makes some really nice shoes that are fitting for this purpose. For Christmas I received the Hipthong model and love them. The crisscross straps across the feet keep your foot stable in the shoe while as a flip flop your heel area remains open and your toe area as well. I'm not sure I would want to take them in the shower as the straps might take too long to dry out (don't know, haven't yet tried, I'll get back on that). I would love to test drive these on the Camino. Chaco can you hear me?
Socks - quantity: 2 and only 2. I bought hiking socks that were made for summer hiking. They were even specifically constructed for your left and right feet respectively. There were frequent discussions amongst the pilgrims about wool versus cotton, changing the socks half way through the day (to avoid sweaty socks that might contribute to blisters), washing the socks or not washing the socks. I washed my socks every day, they dried every day, I didn't change my socks during the day, and I cannot imagine wearing the big fat wool socks during a spring or summer Camino journey. Remember you are walking mostly across Spain (If you begin at St.Jean Pied de Port) and not the Swiss alps. Stick with synthetic, good quality hiking socks, seasonally appropriate to your journey.
Sports Bra - quantity: 2 and only 2. I made the mistake of not thinking about that little plastic circle through which the adjustable shoulder elastic sits. I thought about it a lot while it was being smashed into my skin via my backpack for 26-36 kilmeters per day. When possible choose sports bras without any hard parts, including clasps in the back.
Sunglasses - Definitely. I had a great pair of skiing sunglasses by Uvex that I borrowed. Side protection for the eyes is also nice.
Underwear - quantity: 2 and only 2. For those of us who are accustomed to fresh underpants every day, the 2 and only 2 recommendation is a bit difficult to accept. There is a great desire to sneak that compact 6 pack or set of tiny string panties (they're so small!) in a pocket with all the best intentions and rationalizations. Let me assure you that you will be ok. Think of it this way, it saves time because you won't be agonizing over which pair to wear, or trying to remember which pair is, really clean (believe me physical exhaustion does tricky things to your brain), and your backpack really will be lighter.
Zip-off Pants - I bought two pairs of exactly the same zip-off hiking pants made out of a very lightweight synthetic fabric. My pants had three options: full length, knee length, and 3/4 length. A third of my journey through I woke up to the fact that I needed only one set of zip-offs because I could put that one set on either pair of pants, thus saving the necessity of carrying both sets. I mailed them ahead to Santiago in a packet of other unnecessary items and got rid of a precious few grams of weight. I do recommend having the option of having long pants, not only for chilly morning walking but also for the accidental sunburn on the back of your legs. Being able to cover up can prevent further sunburning and your comfort level will also increase dramatically.
Equipment
Backpack - I agree with those that warn against taking large capacity packs in the over 50 liter range. The problem is: you will fill it. Take some time to acquaint yourself with proper backpack fitting. I tried on several, some very expensive (250-280 euros), listened to sales pitches, and vigorously researched on the internet what I should look for. In the end, I bought a 50 liter backpack from Tchibo during an "outdoor challenge" week for around 49 euros as it seemed to meet the critical requirements and fit my body. It worked out just fine. Things to look out for: A strap across the sternum is very helpful. I noticed a big difference when I would unhook this while walking to a stop to take off my backpack. A water-carrying inner pocket is a must have in my opinion. Reaching for water bottles while walking in side pockets is very difficult. See more under Hydration Device in this section. Things perhaps wished for: One model I tried on had a built-in pocket in the waist belt, similar to a fanny pack. This might be helpful for camera storage. You will want to have it very handy. I carried mine in my hiking pants leg pocket, and it wasn't so easy to bend sideways always to get to it...opening pocket flap, etc. Another problem was that as I lost weight my pants were being pulled down by the weight of the camera, which became increasingly annoying.
Headlamp - buy a small headlamp with an elastic band and a nice bright light. If you are walking in pre-dawn conditions as I did, you will need it. Don't risk taking a tumble over a rock in the dark that can knock you out of your journey or injure you just because you might look silly with a headlamp on your head. Besides, you won't be wearing it long before the dawn comes up, but you will be using it to pack your backpack in the early morning, or finding your way to the toilet in the albergue in the middle of the night, or perhaps needing to see inside your backpack. One pilgrim had a light that had the option of a red light, which I appreciated one early morning because it didn't give off the blinding light that most white light models do. I tried hard not to disturb pilgrims who wanted to sleep later than I did, but the light is necessary in those wee hours. This red light seemed to be a good compromise. Don't forget that last check under the full length of your bed.
Hydration Device - I carried a Camelbak Unbottle 3 liter (100 oz.) carrying device (look under hydration>outdoor on their website) with the insulating sleeve. Hats off to the Camelbak people for designing a very nice product. Design note to Camelbak people: Can you come up with a way for the tube to let the user know how much water is left in your pouch? It is after all in the backpack, out of wearable reach and out of sight. I kept wanting the tube to change color somehow near the valve when it reached near the end of its water supply. Something simple, no LCD displays, no high-tech stuff. I don't know, something like red means less than 1 liter.
Tip: Only fill your Camelbak half full! I was pretty paranoid about finding water in the first days. Water was easy to find. In the more water barren stretches I bought water at small bars and filled back up.
One great advantage of the Camelbak is that you don't have to fish for your water while walking. This is a serious issue. I had great difficulty reaching anything in my side pockets of my backpack. You just can't reach around far enough very easily. With the Camelback you just put the tube in your mouth and drink. Very nice.
Another great help of having the Camelbak is that it really doubled as a portable drinking device at the Albergues at the end of a day's walk. I would take it out of my pack to rinse and refill, then sometimes carry it with me to accompany my "meal" for the evening, hanging it by its strap on the chair. During siesta it would be near my bed, the tube a mere head turn away to drink from while I was writing in my journal or relaxing.
And...if you have access to hot water you could conceivable fill it with water to use like a water bottle for the aches and pains you are going to have.
Organizer for First aid/Toiletries - The folding type, with little compartments for all sorts of things. Keep it compact. This is something I didn't have that I sorely regret. What I had were 2 sets of little bags of various sizes, made of waterproof material with drawstring closure. They drove me nuts. Although they were different colors, thus making an organizational scheme possible, I could never keep straight what was in what. When you are very tired, rooting around in these bags is not fun. However, if you insist on keeping your stuff in bags, this is a good way of avoiding rustle rage which can occur when people pack their stuff in various plastic bags and need to find something.
If the organizer has a loop on the top folding panel it could be possible to bring it with you in a shower stall (there are sometimes hooks), or with the addition of a hooked suction cup you could possibly hang it in a stall with you.
Pocket Knife - carry a simple pocket knife. I carried my super-duper Swiss Army knife that I had owned for over 20 years and it was pretty darn heavy, not to mention unnecessary. Remember you are not going to be required to punch leather, make your own fishing net, or build a tree house à la the Swiss Family Robinson. This isn't survival training. A simple knife is all you need. That said, I was sorry to lose my Swiss Army knife somewhere along the way.
Sleeping Bag - for the spring and summer months you need the lightest sleeping bag you can find. In fact, a couple of walking companions brought only a sleeping bag liner. The were made out of silk, although I have seen cotton ones as well. This was sufficient for the time period. There was only one night that I almost got cold, and in that case I just put on more of my clothing. Many Albergues also have blankets for your use.
Towel - I brought a Speedo swimmers towel. It comes in a plastic tube, is the size of a napkin, and feels like something between fabric and rubber. It is a great product really, because it does exactly what it says. It wicks off all water from your body and it rings out to near dry. For the next Camino I would probably choose to bring a hiker's towel that is a little bigger however. The problem for me was that with my medium long hair I would wick the water away and then begin to freeze as my wet hair dripped down my back. Flipping my head upside down made putting on clothes interesting at times.
Travel Belt/Travel Wallet - I had a travel belt that went around my waist under my clothing. My credit card, health insurance card, and money were kept here. It worked fine, with the only disadvantage being that the money would be soaked with sweat, which I always felt embarassed/sorry about when paying for goods in stores. There are also the models that go around you neck which I often saw on the Camino, but would not personally opt for.
Walking Poles - most important of all: bring 2. I bought cheap poles that had damping and were adjustable in two places along the poles. I am convinced beyond all doubt, that these poles saved considerable wear and tear on my body, saved me from potential injury, and lessened the physical pain I was feeling in the first 6 days. Second most important thing: use them correctly. This means when you are going over the Pyrenees if you start at St. Jean Pied de Port, you should shorten the poles to the appropriate height for going uphill. When you go downhill you lengthen them. Inform yourself about proper use. Do not worry if the first day or in the pre-Camino equipment test drives you feel uncoordinated. It will come with use. I used my poles constantly for balancing over craggy and stony paths, for preventing and/or stopping a dangerous slide, for helping myself up steep hills, for holding onto in front of me for balance when I needed to urinate without taking a 12 kilo backpack off, and last but not least, they make an excellent hat stand. I did wear the pair I had completely out, and there weren't many opportunities (I only saw one near the very end in Sarria) for finding replacement rubber feet. If you can afford the investment, spend money on good poles. Did I mention you need two?
Ziplock Bags - a couple of small ziplock bags is advisable. I used mine for storing bar soap that got slimy from use. You will need one for disposing of any toilet paper, tampons and the like, that you may use while needing to eliminate in the great outdoors. Yes, you should feel obligated to dispose of it properly.
Toiletries
Anti-Diarrhea Medication - take enough for a two day supply. You'll be able to get more if you need to.
Blister Pads -Compeed - highly recommended. Don't bring too many, however. You will be able to buy more on the road. Please heed the instructions and don't wait for a blister to develop. Compeed works best as a preventative measure. When you feel any place or area in your shoe getting hot or starting to rub, stop! Put the compeed on and then continue. They are quite effective and this year I have noticed that the Compeed people have been increasing their line of products. I only got three minor blisters the whole way, and I prevented much bigger problems by using the product correctly. Happy feet=happy pilgrim.
Earplugs - Definitely. I recommend the soft kind you can squeeze. They won't block all noise out, which is actually good, but they will dampen things considerably. Let's all work to prevent Rustle Rage.
Hirshtalg Creme - highly recommended. This is a fatty cream that works like a second skin. It helps to prevent blisters and eases any chaffing. I used it every morning and then again after my shower.
Laundry Detergent - I bought a travel size tube of gel-like laundry detergent. It was quickly gone. It was difficult to find travel size anything in the little supermercados along the way. I ended up using cake laundry soap quite often. This tends to come in super sized blocks which I then cut into manageable slices. You can leave the leftovers in the albergue and within 5 minutes you will notice that it will be gone.
Needle - I would bring only one. I only used a needle to pop a blister once, and I'm not so convinced I needed to. So bring one just in case, make sure you use common sense and sterilize it, but concentrate on blister prevention.
Pain Relief - a few tablets, no more than 5 I would say, should get you started. There are pharmacies along the way. Try to avoid stockpiling first aid supplies. They take up incredible amounts of space and weigh a ton. Trust that you can take an absolute minimum. Remember you are not traversing the desert, and in the albergues many pilgrims are generous when someone needs an aspirin, or a compeed pad, or the like. The hospitaleros(as) have first aid supplies as well.
Piece of String - a reasonable length, such as 4 or 6 meters should do. Mine came in handy the day that there was no area to hang wet clothes, so I rigged an improvisational clothes line on a balcony.
Safety Pins/Clothes Pins - I ended up carrying both, but in retrospect I think the safety pins are more practical and take up considerably less space. They are also more versatile. If your clothes don't completely dry overnight, and you have dry weather the next day, you can use saftey pins to attach your clothes onto the back of your pack and dry as you walk. Many albergues do have clothes pins to use, as well as hanging racks or lines for laundry, but not all. The one drawback to safety pins I can think of is that they are time consuming to fasten when hanging wet laundry on a line. Go for the safety pins.
Shampoo,Conditioner - If you have medium to long hair, bring a bottle that is not the small travel size, but more medium in size. You will run out, and most likely you will have to buy more than what your bottle can hold, but as with all such supplies you can give it to someone else by simply leaving it. I'm one of those who feels that my hair just isn't clean without shampoo.
Soap/Shower Gel/Cream - Some people use an all-in-one shower or soap approach to washing hair, body, and sometimes even their laundry. It's easy to understand why when liquids weigh so much and every gram counts. I took a small bottle of shower gel for my body and it ran out pretty quickly. Near the middle of the trip I began using the cake laundry soap as my body soap because I couldn't find any shower gel. It worked just fine even if not optimally. Laundry soap did work nicely as leg shaving cream, however.
Sunscreen - Absolutely. Keep the bottle medium to small. And most important of all, use it don't just carry it!
Toenail Clipper - depending on how long you are planning to be on the road, this is a necessity. I had to buy a pair on the way because my toenails were beginning to grow too long for comfort. A two-week trip would probably not require toenail clippers.
Toilet Paper - get a roll of toilet paper and remove 3/4 of the paper (or remember to save the next roll that winds down from use to this point). Take out the cardboard middle. Flatten the toilet paper and put it in a ziplock or your toiletries bag. I ended up never using mine. If you need to urinate in the great outdoors you should drip dry. I never had to do more than that outside, so I didn't need it, but it was there just in case. The albergues provide toilet paper, but if overcrowded, you night need to use your own.
Documents
Passport - I didn't need to use it, but I brought it. Tip: Scan your passport and send it to yourself and maybe a trusted family member or friend as an email attachment. If you lose your passport you can retrieve it from any place with internet access. Some of the Albergues have internet access, many do not. Expect extreme long waits and excruciatingly slow response time. Most are coin operated.Pilgrim Passport - you can order one from the various associations for the Camino, or you can wait until you get to St.Jean Pied de Port and get one there. That's what I did. It's conceivable that you may need to get more than one, depending on where you are starting. I saw various styles, and had I walked another week or so I would have needed more space.
Health Insurance - bring proof of health insurance. You never know when you might need it. I ended up going to the hospital in Leon and had no problems with buying medication and being treated because I had this piece of documentation.
Emergency Numbers/Contacts - I wrote these in my journal which was my constant companion. I also left them with a trusted person at home. Email emergency Credit Card contact numbers to yourself and a trusted source before you go, emergency addresses, etc.