You can register for classes on the bates website by clicking on for students on the front page and then on garnet gateway. You should have gotten and ID and pin number in the giant packet that was sent a little while ago.
You can pretty much take any courses you want but they really recommend a first year seminar and there are some areas that you have to take classes in before you graduate.
Registration opened on friday and it doesn't close until sometime in august but many classes are already filled so you should register as soon as possible.
Bates AP policy can be found here:
http://abacus.bates.edu/admin/office...olicy03_04.htm
Hope all of this helps!!!