Good Luck Buddy. It's the best training school I have been through in my Military career.
I went through the school at Fairchild back a few years ago. You don't need to know anything before you go, it will only make the experience better. If someone offers you information or gouge, don't bother. The fact that your a blank slate and get trauma is part of what ingrains it in your memory. Probably the best part of the training. My only suggestion is to bring the gear you would realistically wear in the field. I wore the exact stuff I would be wearing if I ever find myself in a SERE situation. Bag, Flight boots, and they provided the survival vest and ruck that would hopefully be in your aircraft survival kit. If your comfortable surviving in a real type scenario then that's all the better for you. A lot of dudes wore BDU's because they are more comfortable and 2 peices, but I personally think your shorting yourself a little if you do that.
Bring a flashlight with green and red lens (preferably a headlamp for use of your hands). Red is great for night evasion. Other than that a good knife and some camping TP. Really just the same type crap you are used to for a overnight camp. Someone in my group brought a few bullion cubes for Thumper. It helped a little for the flavor. Hot Sauce might help as well. Immodium might help you keep from crapping while in uncomfortable situations. Good sunglasses and hot weather undershirts.
Thats all I can think of right now.
Let us know how it goes!