Since you're looking for a good help book for med chem check out Lippincott's Review of Organic Functional Groups, 4th edition (ISBN: 0-7817-4381-8). It's a small and cheap book (used), but has been a good reference for reminding me of all the O-chem I forgot. As the name implies it focuses on functional group properties, which is what a couple of my professors have emphasized in our med chem lectures. See if your school library has it, that's what I did before buying the textbooks I have. I scanned through Foye's and found it to be more like the ramblings of an old chem professor who goes on and on about more stuff than I needed to know about. Then there's also Wilson & Gisvold's Textbook of Organic Medicinal and Pharmaceutical Chemistry but I haven't looked through this one yet.