I didn't have the best gouge when I took the test. I prepped by reading parts of "Aerodynamics for Naval Aviators" and memorizing some formulas in "Everything Explained for the Professional Pilot." Those are a couple good books along with some other resources out there.

In addition to a seminar (Emerald Coast Consulting) I read a book on how to present yourself and do well in job interviews (can't recall the title). ECC was good prep, but I ran my experience there by a friend flying the line at Delta and he had some good advice to tweak what I had gotten from the seminar. Use your resources.