honestly, I wouldn't read much of anything. It is far too difficult to gauge the appropriate depth before you start. But fwiw here are the books I used:
CRR:
Boron, Lilly Pathophys of heart disease, West respiratory
SSB:
Blumenfeld, Purves
ERG:
Mosby series endocrinology and gastrophys books, boron
Overall: First Aid for USMLE (good figures), an anatomy text (they are all pretty similar, find one that works for you). Bates (physical exam book). I wouldn't buy the updated first of Boron, get the second edition. I have 1u and there is some pretty important stuff missing from it. esp in endocrine because endocrinologists keep changing their minds.
Books in bold I would consider to be absolute musts. Boron is the preferred text by faculty and they use figures from it often. Lilly is just THE best book, written by MDs and Med students, West is a book the resp. guy here uses.
If you want to read something over the summer or learn something, have a look at some basic clinical testing, CBC, Chem, UA, and see what goes into them and have an idea of what they might mean, but if you go any deeper than wiki, you went too far.
Looking forward to meeting you all too, it's going to be a blast and lots of hard work I'm sure!
