We included a lot of information about the PMP exam -- how it's structured, what kind of information it covers, where to find more information -- in our free 200-question sample exam. You can download it as a PDF here:
http://www.headfirstlabs.com/PMP/free_exam/
Andrew Stellman
Author of Head First Agile, Learning Agile, Beautiful Teams, Head First C#, Head First PMP, and Applied Software Project Management (O'Reilly)