I am brand new to the concept of backpacking. I have done quite a bit of camping in the past, but never more than a few miles from the car. I am looking for advice on the right pack to get me started. At this point, I'm looking for something that is an appropriate size for shorter trips (a night or two, maybe three?). I realize that going into a store to try them on is probably my best option, but I'm looking for any pointers regarding what to look for!