+1 on Mountain House meals, but I would recommend that you sample the meals before packing them into the woods for an extended stay/hike - it's no fun packing in a bunch of meals only to discover you can't stomach them.
For multi-day hikes, I generally pack some or all of the following:
- Breakfast: instant oatmeal or cream of wheat and a couple ziplocks with brown sugar and raisins.
- Lunch: pita bread or soft tortilla shells (light weight and usually long lasting), PB & J in tubes, tuna packed in bags (not cans) and some packets of mayo and relish, a stick of summer sausage, possibly some cheddar cheese.
- Dinner: Mountain House (or similar) meals, instant mashed potatoes and a gravy packet, ramen noodles... hopefully some trout too. In addition to my planned dinners, I always pack a few extra small packets of Lipton chicken noodle soup (or similar) so that I have something I can make quickly if the weather turns and I need something in me to warm-up.
- Snack: Mountain mix/gorp (great, but heavy), dried fruit or fruit leather, Eatmore candy bars (I haven't seen these State-side, so I grab a case from Costco when I'm in Canada), possibly Snickers, if it's not going to be too hot. I sometimes pack some energy bars, such as a Cliff bar, but tend not to like most of these.
- Drinks: drink crystals to add to water and I always bring some hot chocolate, but that's because I grew up hiking in the Alberta Rockies where summer hikes could quickly and unexpectedly turn chilly.
- Other: small salt an pepper shaker, packets of mayo, relish, ketchup and hot sauce.
Enjoy the hike. Have you decided where you are going?