Thats true, you should prooobbably just relax, try to get in shape (seeing as time will be scarce) and get yourself in a routine-type mode.
However, if you really want to study, here's something I wish I would've done before I went to undergrad and took o-chem/gen chem/phys with TERRIBLE professors (I was a science major): Try getting some MCAT study/prep material and look it over. Not to learn it, but just to get a basic idea of some of the concepts. I remember the first time I started studying for the MCAT thinking 'man, i wish i had seen this stuff before I took (and did mediocre) in a lot of my undergrad science classes.' Several of the prep books kinda digest the information and give it to you in a way you can understand, so I think it would probably help if you looked at that beforehand. Also, several of the post-bac course curriculums are geared toward the stuff specific to the MCAT and medicine, seeing as the range of students isn't as wide as a normal undergrad course.
There's my 2c. Take it, leave it; nonetheless, its gonna be a crazy year. Good luck!