1) Use BRS Histo or RRS histology/cell bio. There's some patho in both, but not too much that will mess you up. Reading the BRS histo book two-three times through and being familiar with the overall ideas in each chapter should serve you well. Extreme minutae you see in these books aren't very high yield. Some courses also don't cover the neuro-related topics of certain organs like the retina and organ of Corti...if you haven't, be sure to take a look over them. I saw several questions dealing with all five senses in a neuro aspect.
2) Be familiar with genes and cell cycle transcription factors. You may have thought that you were done with stuff like p53 and CDK when biochem was done, but I saw a good number of questions like those on my exam. You don't have to go in the same level of detail, but be sure you're familiar with them.
3) On that note, the histology test seems more like of an integrative test that tests stuff also from physiology, anatomy, biochemistry, and neuro. Be prepared to use knowledge from other subjects for this test.
4) Last, doing well in the class and being familiar with the pictorial aspects of histology is ultimately going to be your biggest friend or enemy. If you don't remember much of what you learned earlier as you're reading a review book, you need to double time it and continue reading BRS/RRS.
If you're wondering, I got a 90 on mine. Don't believe people that say it's the easiest NBME you'll take your M1 year...last year's class said that and we were blown away by the amount of random crap on our test. In fact, I'd venture to say it was one of the hardest tests I had.
