Checklist for Success by Cage is a must.
My favorites for prepping for the Technical stuff are:
Airline Pilot Technical Interview - A Study Guide by Ronald McElroy (also published by Cage Publishing)
The Pilot's Airline Technical Interview Reference Manual - by Capt. Bob Norris available through AIR Inc. (Don't flame me, I'm not a Kit Darby proponent, but this book is awesome. It's a collection of articles by different people on Meteorology, Systems, Aero, Sims, Pilot Techniques, Operations, and Medical.)
AIM/FAR