Get a copy of those Kaplan Step 2 lecture notes for surgery on the S: drive. Borrow from an upperclassman if you want to save trees. Many students swear by these.
Most students also like Case Files and I used them for every clerkship.
And finally…the surgery shelf is pretty difficult — likely one of the hardest. Especially if it's your first shelf I'd recommend doing a lot of questions to get the feel of taking a shelf exam (they're only 100 questions each but the stems can be long and it feels pretty intense!) and re-reading the books that you choose.
Good luck!