Stock photos are perfectly fine man. If you have the choice I would always go into the class and learn live. But for the time being stock photos are a great way to study anatomy and start learning the basic elements of good draftsmanship.
Dear AnimatedBuzz, I've missed you! Animation school sure keeps ya busy, huh? In the throes of making a stop motion group film this summer under the guidance of Stephen Chiodo. Holy crap that stuff is hard work.