I just took the GMAT late last year (and am in an MBA program now). Any two of the books from the major vendors should be fine (Peterson's, Arco, etc). I also highly recommend the practice problems book from ETS which has the *real* problems from prior tests. This is very helpful. You should also take the practice tests from MBA.com They are very representative of what you will actually score on the test (though you should take these practice tests before going through the ETS book to get an accurate estimate). Good luck! -Dharmesh