I used High-Yield Behavioral Science and First Aid for it and that was more than enough. The patient communication/ethics type questions are what are tough, so check out Q-bank's explanations on those as well as the section in High Yield. ( These are the "patient comes in with blah-blah-blah going on...what do you say/do next" questions. ) Review developmental landmarks and defense mechanisms too. Symptoms of intoxication and withdrawal of the different drug categories are also worth looking over.
Our school recommended to us that we use High-Yield B.S. for our quick review (it's a one day read, unlike BRS) and everyone I know had B.S. as one of their best sections. Don't sacrifice studying for other subjects to overload on the B.S. questions. The majority of B.S. questions are NOT psychiatric in nature, so don't spend time memorizing DSM-IV criteria (they never give you that much info in the questions to be able to check off criteria. Pick the obvious choice for the psychiatric disorder questions, you'll be right 95% of the time).