As far as study materials go.... there are a TON of different series out there, find one you enjoy and go with that... Case Files, Blueprints, Step Up to Medicine, First Aid, etc...
A lot of folks get a subscription UWorld or another online question bank, helps with Step II and shelf exams.
And then on rotations, just be a team player. Attitude is probably one of the biggest things that can make or break you. Definitely don't need to be a kiss ass, but be on time, don't complain, know everything about the patients you're assigned to, offer to help if you currently have nothing to do, read about your patients during down time, be prepared for rounds, help your intern/resident by looking things up for him/her, if you find a good article or relevant piece of info about a patient you are working up then make copies and share it with the team, etc... mostly common sense stuff I hope.
Don't try to show up your fellow classmates, it shows. If on rounds your attending is pimping your classmate and they stumble with an answer don't jump in with your answer. Don't complain about hours to your intern when they're on track to have a 90hr week.... etc...