for me, water water water, bread and dried meat or some nuts, maybe a couple cans of soup with easy off lids, a bit of salt and a bottle of hot sauce, a bit of para cord to play with, a few knives to play with, see how well they hold their edges, more playing. a book, DEET oh, and more water.
about 25-30 pounds, mostly water weight, next summer I'm going to add a spray bottle since I don't sweat much even when it's hot.
I'd also recommend adding a metal coat hanger, my personal experience with a backpack and a failed adjustment buckle (link for a pic of the type of buckle I'm talking about)
http://i.ehow.com/images/GlobalPhoto/Articles/4877769/Brokenstrapbuckle-main_Full.jpg
Just take the hanger and bend it into the shape of the buckle, I had one break while out hiking, one shoulder carrying th weight is no fun, fixed it after I got home, doesn't look great but it holds the weight very well.
I'm now in favor of metal buckles instead of plastic for this reason alone, and I carry another section of hanger incase the other buckle decides to break on me.