Please understand one thing before we get started. I am FAR from an expert! I have done a bit of travel with food though and have gotten some good ideas from friends, experience and the Internet. These I will share now. if anyone who reads this has any other ideas please email them to me and I will get them posted ASAP. With that said- On to my small bit of knowledge!
OK, first things first. Please understand context. I deal with trips lasting from overnight to 3 nights. That is one thing that decides what and how you bring things. I will freeze meats and poultry prior to the trip and store them in a cooler covered in ice (pack at bottom, sealed in double zip style baggies). They will thaw but not as quickly and I've had burgers last a whole 3 night 4 day camping trip and come home still mostly frozen.
There are tons of sites that can tell you how to pack a cooler and sites that will sell you coolers or inform you of your choices including http://www.colemanoutdoors.com/ and http://www.coleman.com/ So I won't bore you with that information here.(no I'm not a salesperson for Coleman, I won't receive a kickback, I simply like the products and happen to have found both sites helpful). I personally make sure everything is sealed very well, bring extra bags just in case and make sure before leaving that the campsite I'm headed to has ice available.
I try and pack small amounts of condiments rather than fit large ketchup or mustard bottles in with our gear. There are many small multi spice containers that you can get either pre-filled or empty to fill with your choice of good camping seasonings. I stay away from most prepared foods but some are great! Baked beans or other canned goods store well, heat rapidly and are filling. Fruit can be cut ahead of time or if you wish, bring a decent knife with you rolled up in a towel to protect both the knife blade and your fingers. I use a small camping cutting board and bring a few knives as I tend to cut my veggies up as needed. For some veggies though you could just cut them to a rough dice or strips then finish them as needed on site. By packing things that I use together in the same large bag I save time when searching through the cooler thus letting me conserve the cold. Examples would be Mountain Pie fillings all go in one gallon size baggy-shredded or sliced cheeses, pepperoni or sliced veggies all in their own bags get bundled into one large package. Drinks are in a separate cooler (using drink boxes or foil packed things like Capri Suns (TM) enables you to freeze them and enjoy them as slushes plus using them as ice packs).
Fill empty space with balled up newspapers to conserve the cold and remember to put things back in as soon as you're done with them. personally I love the challenge of cooking lots of cool stuff at campsites but a few good basics are always welcome!
