I'm a Marine in Iraq right now and am glad to be able to help you. Boot camp will require alot of endurance from you. I haven't been lifting weights for about three years but instead have followed a program of calisthenics only (i.e. pushups, pullups, dips, bodyweight squats, bridging, etc.) These are the exercises you need to be doing if you want to have a good headstart at boot camp. By no means am I suggesting that you should drop the weights, but it makes sense to train using your bodyweight if that's mainly what you'll be using as a source of resistance at recruit training. Also, notice that the Marine Corps Physical Fitness Test doesn't test you using weights.
As for the frequency of your workouts, think about how animals in the wild are. They are constantly moving around, climbing, running, crawling, etc. They don't separate their training by body parts. You need to be the same way. What this basically means is that you should do SOMETHING everyday. But you need to make sure you stagger the intensity of your workouts. Don't expect to be able to go all out every day of the week. And, on some days, if your body is telling you that it needs rest, listen to it.
Anyway, I'd be happy to answer any questions you'd have on working out, the Marine Corps, or fitness in general. You can PM meif you've got anything on your mind you'd like to ask me. Good luck preparing for recruit training.