Nathan,
Matt truely hit it on the head. One of the worst mistakes you can probably make is trying to get TOO FAR ahead of yourself in this program. There are so many hurdles to this program, that you have to take each one in stride.
I am definitely not saying that it isn't beneficial to study and prepare ahead, but it just doesn't make sense to be study the T34 Emergency Procedures Flash Cards that you just bought at Wings in Pensacola when your API Weater Exam is tomorrow morning! You will have enough time in between stages of training to get prepared for the next step.
On the flipside of things, find a good group of friends and go out and "decompress", whether it is working out, playing golf, hitting Seville's (ah Marines and Teens, and Squids and Kids night... lol), or just hanging out with your friends, have something else to help balance out the stress that the program is going to put you under, and to help you recharge the batteries so to speak.
When it comes to gouge, you definitely have to remember that the BEST source, and the one you are responsible for, are the books that are provided to you. As Matt can probably agree, I have seen people study the gouge, and only the gouge, and pay the price for it. Maybe there was a change to the books since that gouge was written two years ago, or maybe you don't get that really indepth knowledge of how a system or procedure works, and that will show up in a brief. My own personal belief is that gouge can serve as a great post studying tool to help you find out areas you may need to know better. In the end, you will find your own comfort level with trusting the gouge, some of my friends don't even use it since they have been burnt by it in the past.
Best of luck in training and OCS!