These are the best-rated obstetrics/gynecology rotation resources as reviewed by the students at Harvard Medical School.

Essential

USMLEWorld Step 2 CK OB/GYN Questions

uWISE Questions

Notable

Case Files Obstetrics and Gynecology 3rd Edition  Note: 4th Edition is coming out in September 2012
PreTest Obstetrics And Gynecology 13th Edition

Decent

Beckman’s Obstetrics and Gynecology, 6th Edition