I think it depends on which classes you are going to be taking, and which ones you've already taken. If by Biology classes, you mean A&P and Micro, not General Biology (assuming you've had General Biology), then you could probably just be sure to read the first 2-3 chapters of your textbook in the weeks before class starts.
I am almost finished with A&P I and Micro right now and there was definitely some review in the beginning...however, the instructor assumes you know the stuff from Gen. Bio and doesn't spend much time on it. This was especially true for A&P...the first 3 chapters were mostly review of Gen Bio. It had been 15 yrs since I had Biology so I was VERY glad that I had read those chapters before class started.
Knowledge is power (and helps you get a better grade!), so it sure wouldn't hurt to check out Barnes and Noble too. Good Luck!