One of the big mental blocks I see in my own school is the "I'm not touching a book" mentality.
One thing I've noticed of many high performers in my class: they read. No one expects you to read material that isn't relevant, but there are several good books out there for a variety of the subjects. At my school, it is pretty common to see 5-15% of test material that comes straight from the recommended readings. We also have several classes where they provide "suggested" supplementary resources such as USMLE/COMLEX style questions books. Pro tip: I've had entire exams that very closely mimic the style and material covered in those books. One of the problems with many subjects in medical school is translating what is presented into what is testable. The common link is that medical school exams tend to very heavily focus on what is clinically important. Ok, you say, that makes sense. Duh. The problem is then translating it into exactly how it will be questioned. The question books are good sources and many faculty tend to copy the premise of the questions.
Next, PPT slides and class notes depend heavily on the competence of the faculty member putting the resources together. There is a big difference between being an active, engaged presenter and being able to properly develop a PPT presentation. We have one entire department at my school where the information in the PPT is so simplified that you could never walk way with a good understanding of the material. You absolutely have to read if you want to perform well on the exam because, surprise, they test the material at a level of difficulty to be expected on the boards.
Finally, do not buy every single recommended text. You probably don't even need to buy every required text. I would recommend buying at least one major textbook in every subject you study, if only for reference. Costanzo or Guyton for physiology and a copy of Robbins (pathology) is a must. There are several good biochemistry texts and I'd recommend buying one (probably the suggest text), especially given how often the subject reappears in each system. Buy an anatomy text and atlas. The Haines neuro atlas is a must in my mind. BRS physio is good and it's a resource that I reference pretty routinely. Pathoma is a good investment. Some of the individual systems cover material in such a way that a textbook can be useless, so you have to evaluate those resources on a case by case basis. If you're in a lecture-based school, textbooks are most useful if the professor closely follows their layout, so as to reinforce information.
