Socks are extremely important. You need to wear two kinds. First, against the skin, you need
a synthetic "wicking" sock (ask for it at a sporting goods store or contact Eastern Mountain
Sports). Over that wear a heavy wool sock. I know of no synthetic substitute. More important
than any other item of clothing, carry at least one extra pair of these two socks. Two pair is
Pour a box of regular cooking corn starch into a zip lock bag and include in your pack to use as foot powder, and powder all over when changing into dry cloths. This works much better than even commercial "corn starch" powder. Whether in wet weather or dry, change your socks at least twice a day. Attach the ones you just replaced to your pack to dry and air out, even if they only "drain".
Pamper your feet and be aware of any problem that develops and attend to it as quickly as possible. The first few days of walking, cut your walking time by as much as half of what you think you can do. Give your feet a chance to adjust. If you aren't used to hiking with your pack, be sure to include a couple packages of "mole skins" from the drug store and apply immediately to any area where your feet feel "tender" or start to blister. Army boots are much less inclined to cause this sort of problem than even the most expensive "hiking boots", in my experience.
Offered by Ron.