Last summer I asked the same questions and everyone told me to just "relax." law school (esp. the first year) will drain most of your energy. It's like amarathon (or hazing experience)...So I would say try to relax, and if you want, pick a few easy legally related books to read, but not too much.
Some people take those prep classes. It might work, it might now. You can't really learn how to take exams until you know the materials. Plus, here in UB, BarBri always hold those final exam prep classes, so it's not a problem if you join BarBri or other similar prep programs.
Even though people say to be in law school you don't need to have legal background, a lot of people here have taken law classes (community and or college courses, previous paralegal or legal assistance career, etc.) so I would suggest (if you don't have any legal background at all), start reading the news about legal issues.
I am not sure how these "WON L" books & related resources would help or not. I bought them and never got past page 20. Each school is different and person experiences are different. You'll just have to try for yourself.
If you do come to law school, please don't hesitate to contact me. I would be more than happy to help you in person too. I found my upperclassmen more helpful as mentors than any books. I hope I can do the same for you & the incoming 1L's.
I am very involved in clubs and moot court. If you do attend UB and is thinking about joining extra-curricular activities, please let me know.
Send me a private message if you have any further questions. Good luck!