This is a sample list of things you might take on a week-long trip hiking in a wilderness area. Even more than with other kinds of travel, packing for this kind of trip requires compromises between keeping weight down and making sure you bring everything you'll need, because you have to carry it all with you. Depending on where you're going and the time of year, some of the items may not be useful to you, and there are inevitably additional items you'll want to bring along, but this should give you a general idea of what you'll want to pack. (Please keep in mind that we want this list to be useful to people in general, so don't edit it for your own specific needs.) For information and advice about gear selection, see Wilderness backpacking.
2 synthetic undershirts
2 long-sleeve shirts
2 pair of pants (suitable weight for current weather)
2 pair of underwear
2 pair of wool socks
sandals (for wearing when not hiking)
waterproof windbreaker, or at least a jacket.
raingear - ponchoes can drape over your pack and save you the expense of a waterproof packcover.
women: 2 good sports bras
oatmeal, cereal bars, trail mix, sausage
gas camping stove, matches
dish cloth, scouring sponge
multi-tool pocket knife (e.g. Swiss Army or Leatherman)
plastic bag for trash
water filter or iodine tablets
foam or air mattress
headlamp or flashlight, spare battery
maps, compass - make sure you can read them before you set out.