Most rotations, I think I focused on one or two core books. Not that there aren't other good ones out there, but this is what I used, FWIW:
Family Medicine: Blueprints, Ambulatory Medicine section of Step Up to Medicine
Medicine: Step Up to Medicine, MKSAP, USMLE World Step 2 CK questions (useful for most rotations, but particularly this one)
Neurology: Blueprints
OB/Gyn: Case Files, uWise, to a lesser extent Blueprints
Peds: BRS
Psych: Case Files, First Aid for the Psych Clerkship
Surgery: NMS Surgery Casebook; I didn't use this, but a lot of people in my class used Step Up to Medicine and after the shelf, I would use this too as that's essentially what the shelf was
Case Files is fine for almost every rotation, but I found them particularly useful for Psych and OB/Gyn. For whatever reason I felt like some of the other ones a few more random, useless cases; additionally, those two rotations have a relatively narrow scope of things you need to know, so you have a better shot of getting a semi-comprehensive look by just going over those 60 cases.
Of course, these were just what I used. As mentioned above, these questions have been beaten to death in other threads, so feel free to do a search.
