Just what you needed... more books to read from! In all seriousness these books are there to help with learning some dry and more mathematical subjects. They make the learning fun and help the concepts to stick. Many practice scenarios similar to medical exams as well as questions designed the teach the material. These are HIGHLY testable. Do not make the mistake of ignoring ANY of these subjects. Click on the image for a link.
After all, your patients do not care about your exam score, only that you have mastered the material enough to help them live.
I would also recommend the EKG book which is great at teaching EKG basics in the same interactive manner. Again, super high yield for the time investment.