Determine where you fall in the scheme of things and plan your purchases accordingly. PBL represents a more integrated way of presenting the materials. Groups meet and are given clinical situations in keeping with the current subject material. These situations can involve anatomy, pathology, pharmacology, etc. That said, PBL is not for everyone.
Some people prefer the lectures.
Some schools offer only PBL, some only traditional, and some give you an option of which you would prefer. Contact the schools you are interested in and ask them about their curricula. There is as much free time as you want there to be. In spite of what you might hear, medical students don't study ten hours a night AND go to every lecture AND go to every lab AND read journals just for interest AND work on a cure for cancer. At the beginning, sure, you'll feel this overwhelming fear that everyone is ahead of you and you will make the lowest grade and somehow people will find out and point and laugh at you.