Took the Biochem shelf in December 2003. Studied class notes and the Champe & Harvey (aka Lippincott's) review book. Don't get stressed when you see the pharm and endocrine looking questions; you can answer them with biochem knowledge. Good luck!
The shelf exam was worth 1/4 of our overall grade and we received credit based on our percentile score on the shelf exam. Since the final overall class grades were used to determine the curve, I really don't know how much the shelf exam alone factored into the magnitude of the curve.
Make sure u know the biochem part of First Aid cold!!! I took the biochem NBME last december and looking over First Aid saved me. Almost everything from first AID was on there.
Also go to the NBME website and look at the biochem sample questions. Usually those 5 questions will be on the exam. Alteast this happened for my histology and anatomy NBME.
Lippincott was good. There was some metabolism questions as well. Like u should know that 3500 calories should make a pound of fat. And someone trying to lose a pound a week should decrease calorie intake from 3000 to 2500. Those questions were on the exam, and they normally dont teach that stuff in biochem class.