My go to resources were:
-the Turkey Book: great prep guide before specific rotations; I usually reviewed the rotation specialty the weekend before starting a new rotation.
-PDF of high yield shelf notes: loved this resource, especially for my surgery, psych, and peds rotations; I used this to supplement my own study materials
-PANCE prep pearls and the USMLE Step 2 CK book: during clinical year, I personally reached for the USMLE book more, but relied on PANCE prep pearls for studying for end of rotation tests
-other High yield PDFs (internal medicine, pediatrics, surgery): good for quick review, buzzwords, and recognizing common associations
-Question banks: my school gave us access to ExamMaster, so I would try to quiz myself as much as possible