How about the easy answers that have nothing to do with reading?
Get in shape, for all those long nights of studying/writing/stressing. Go to the gym.
Do some recreational stuff you wont have time for when you're busy, like talking to your SO. Also, camping is awesome.
Learn how to cook something nutritious and filling in five minutes, or just figure out what restaurants you will eat at.
Kick some bad habits, like smoking or coffee drinking. That way you can female dog about what law school is doing to you when you pick them back up. Everyone needs bitching material.
Read all those books you always wanted to read. Chances are you won't have much time to do it after you start law school.
On a more serious note: Check out Law Preview, it's a week long course to teach you all the basic material/give you an overview. The idea is that you will be better prepared for you first year afterwords. I'm thinking about it. BAR/BRI has a similar course I believe.
I think the suggestions of the other posters were correct, if not quite as specific as they could have been. Pick up a law school prep book, if you are still stressed about it. I liked law school confidential
Personally, I plan on just relaxing, then moving in a few weeks early so I can get settled.
Just my two cents as a fellow 0L