The MOC - go to the boards website and look at the "list of topics" that they put there. That is by far the most important thing. They essentially give you the topic of each question. Some are very vague, some are fairly specific. So if it says "melanoma" it doesn't help. But if it says "spectrin-deficient hereditary anemias" then you know what to look up (use any reference). I didn't really do much more than that.