I used the Saint-Frances Guide to Outpatient Medicine. Its pretty small and fits in your lab coat... over 700 pages, and covers the topics that you'll need. It saved my butt on my FP rotations many times over... especially on things like HTN and DM, it breaks it down for you algorithmically.
Q
The best question book for the Family Medicine NBME shelf exam is the NMS Q&A book. Awesome questions and explanations, very similar to the real thing. Swanson's was too wordy for me...