I second the recommendation for
The Complete Walt Disney World! We purchased this one before our trip last month and I really enjoyed reading it. As PrincessSuzanne says, it doesn't give great info on the resorts, but I had a Passporter as well (LOVED the pockets, they were a
life saver for organizational purposes) and it has awesome resort info.
The Complete WDW is such fun to read... I thought I knew just about everything there was to know about WDW, and I still learned a lot of fun new trivia and info from this book. It has great pictures too. The authors are Julie and Mike Neal.
I would say get yourself a PassPorter for the organization, maps, and general info.. I would never travel without one.. then get the Complete Guide for fun.