Most of the shelf exam is medical care of surgical patients. Heavily weighted items are things with postop care like fluids and electrolytes, infections (causes of fever, etc), end emergent situations (know trauma cold and post-op emergencies like evisceration through an incision). Specific diseases are tested somewhat - know the good diagnostic tests and which radiology tests to order- ultrasound vs. plain film vs. CT vs. MRI vs. exploratory lap. This kind of thing is best studied on a disease by disease basis, like cholelithiasis, then move on to choledocholithiasis, etc. If you've got the time, NMS Surgery rocks IMHO. You can be somewhat selective in which chapters of that you read.
The strategy to get pimp questions right, in contrast, is totally different. Netters and Surg Recall are pretty key. You will get asked anatomy questions hardcore, and bizarre questions about everything from what kind of suture and stitches should be used for different situation to what kind of surgical approach you should make to who was DeBakey and Sister Mary Joseph. Some they will expect you to get and think you are stupid if you don't, others they don't want you to get because they want to show off (like how many surgeons have won the Nobel Prize). Anyway, none of the stuff I just mentioned, including anatomy and surgical approaches, will come anywhere near the shelf boards.
bpkurtz