1000+ PMP questions: if you consider buying the PMP Exam Prep Questions by Christopher Scordo....

 ....and you are currently enrolled as a student (my participation at NYU SCPS for a semester was accepted wothout a problem), you may want to consider a membership with the PMI first.  You don't have to be a credentialed PMP for a membership and you can access this book online for free there.  Needless to say that there are tons of other books for free accessible with the PMI membership but who has the time to read all that interesting stuff when preparing for the exam.