The experienced pilgrims have covered almost everything you asked about or needed to know. I will add my two cents worth - okay maybe eight cents worth) about the critical need to have both your boots and rucksack properly fitted by someone who knows what they are doing.
No two people are built the same way. Even someone with your same general build will have shoulder, hip and arm bones that sit differently. I have also learned over the decades that everyone has slightly different feet owing to the underlying bone structure that is unique to each human.
I will separate my contribution into bits, Boots and Backpack /rucksack. So here goes:
BOOTS:
As a general rule, your hiking shoe or boot size should be at least one full-size LARGER than your normal street shoe size. I wear a US size 11 (45) street shoe and a US 13 (47) hiking boot. But my Keen boots run 1/2 size small. So my size 13 boots are really a 12.5 - 1 1/2.
This oversizing is to allow about 1/2 size for the extra, thicker socks you wear, and another 1/2 half size for swelling as you walk. Your feet will swell both due to heat and the weight you are carrying. Also, fit the boots with the socks you plan to wear while walking.
The choice to wear a low shoe or mid-ankle boot is a personal one. As a large framed fellow and carrying about 13 kilos, I found it better to have the additional support the ankle-high boots provided. They were also warm and better for splashing about in the many, many puddles along The Way.
Remember as you read this that if you ask 10 pilgrims what boot & sock arrangement they use and you will likely receive 15 opinions. This is my position based on a lot of research and my personal experience walking the
Camino Frances last year. I had not one blister - not one. Perhaps it was luck. Who knows? I also paid close attention to what problems the other pilgrims around me were having with their feet and choice of footwear.
Anyway, when you hike you will likely wear two pairs of socks. The inner layer is usually a thin liner sock of silk or a poly, "Cool Max" type material. They could even be a pair of "nylon" ankle socks you already have. This liner wicks moisture from your skin and reduces friction between your feet and the boot / shoe. I now prefer dark colors (black, navy, brown) to light colors (white, tan, grey). After five weeks of walking, the white ones I used last year were very "funky" and went in the trash. I think the darker colors will look better longer.
The second, outer pair of socks probably should be something like "Smart Wool" brand Merino wool. They are thick, provide really good padding and protection, are hypoallergenic, and do not stink easily. They also hand wash rather well. They dry quickly too.
When fitting the boots, make sure your heel is firmly back in the heel counter or box. Lace the boots to ensure your foot does not slide forward on level ground. If the store has a simulated slope, ramp, or stairs, walk up and down them. When walking DOWN, your toes should NEVER touch the inside of the toe box. That causes blisters and smashed toe nails - yuck.
I also suggest you try looking at this forum conversation for further advice copy and paste the entire thread into your address box):
http://www.caminodesantiago.me/comm...Compostela+(Camino+de+Santiago+de+Compostela)
BACKPACK / RUCKSACK:
Again, no two people are built exactly the same. Try to find a shop where they have an experienced hiker / backpacker who knows how to fit a backpack. Several better backpack brands (Deuter, Gregory, Osprey) use a plastic fitting frame to measure your torso. All are good brands, offering value and reliability for the cost. You will see a lot of them on the Camino. Choose a pack based on fit and features you want. (TIP) What "looks" best, may not fit best.
The "best" backpacks for a Camino is one the fits
you "best." The better packs, intended for serious trail use, will have a padded waist / hip belt, some sort of a back pad / suspension system that allows air to circulate between your back and the pack for ventilation, a chest / sternum strap, and UPPER shoulder harness adjustment straps. Many will also have pockets for an optional hydration bladder system.
All backpacks have lower shoulder strap adjustments. However, the difference between a casual, school or day pack intended to be slung and unslung easily and a serious hiking backpack that will stay on your back for several hours at a time seems to be having upper shoulder harness adjustment straps. This allows you to snug the pack high and tight to your shoulders. This reduces shoulder and back strain and pain.
There appears to be a "Sweet Spot" for many pilgrims who have clothes that are small to pack, of 32 - 35 liters. Again, just my observation, but the Osprey Talon 33 (M) / Tempest 30 (F) liter series seem to be very popular. For sake of integrity, I use an Osprey Kestrel 48 liter rucksack in Foliage Green. All my clothing is very large - likely double the weight and volume of yours. Plus, for health reasons, I must carry additional nutritional stuff. So, my all-in rucksack weight is necessarily more than the 10 % recommendation.
When correctly fitted, the backpack weight should ride mostly on the hip belt and should sit on top of your Iliac Crest (loop). That is the big "wing bone" of your pelvis or hips that projects (if you are of thin build). I must press in a bit to feel along my waist to find it. It is the shelf-like, projecting bit where mothers sit their toddlers. Anyway, this allows the weight of your pack to be carried mostly by your hips and legs and not your shoulders and back. After 25 - 30 Km it WILL feel better.
Final point, when you try the pack on in a shop, ask to place weight in the pack approximating the weight you will carry. The local REI store I use has sandbags in five-pound increments to add to any backpack. I use 25 pounds for ME. You would likely use less. Anything heavy will work. If they do not have sandbags try propane cylinders, sideways - they are dense and heavy.
The point is to walk around in the store with the loaded backpack on for 20-30 minutes to see how it feels. Have the salesperson help you adjust it properly so it fits you comfortably. Only after you do this, would I recommend committing to buying a particular backpack / rucksack.
WALKING POLES:
Doug is absolutely correct in everything he says about walking poles and staffs. I used a pair of Leki hiking poles with the classic twist adjustment. They saved my Camino and likely my life when I was forced by a mountain biker coming downhill at speed to jump off the path (downhill - the stupid way of course) whilst hiking up Alto de Perdon. The right-hand pole bore my weight and literally prevented me from falling off the mountain.
That said, I cannot imagine NOT having a pair of quality poles with me. I retired the über lightweight pair I used last year, in favor of a slightly heavier diameter model this year. I also fitted removable LED blinky lights to alert oncoming drivers in poor weather, one to a pole.
I also disagree with the video above. By gripping my poles all the day long, I developed a medical condition known as (seriously) "Trigger Finger" in my left pinkie finger. It was more an inconvenience than a hindrance. But it still hurt. Only a cortisone injection after my return solved the problem. But the finger is still sore. This year, I am arranging to have the injection about a week before I leave for France in April.
The poles are handy for other things besides stability, traction and safety. If you were ever to meet an unfriendly dog (frankly, I think this is Camino myth), the pole could come in handy. I use mine to hang laundry from under the upper bunk in an albergue by using 2 "S" hooks on each pole to suspend the pole from the bed spring above. Large rubber bands also work well wrapped through the springs or slats and around the pole. Of course, this only works if you have the lower bunk...
Poles are also usable as tent poles for using lightweight tents or tarps for shelter, if you go that way.
I hope this helps.