In addition to the Kaplan blue book and the DAT Destroyer, I used the Princeton Review Series - MCAT Review. Check the medical student forum for a copy - it's the hyperlearning series, which is a fat book that covers G-chem really well. From the G-Chem portion of my first and latest exam, the one thing I remember them stressing is pattern recognition. Know cold orbital designations, BDE trends, bp/freezing point trends (colligative properties in general), phase diagrams (interpret certain lines ie. the properties of ice and water), and etc. Get to a point where you can identify the topic, and be able to quickly identify functional groups or trends. Of all the science sections, I thought GC was the easiest to prepare for, but Bio required the most time to prepare for (in anticipation of all sort of left field type questions). OC was probably the most difficult for me to prepare for.