I used the GMAT for Dummies and old Arco book from 2000. I only took the practice test in that book and scored 500 each time but I had made some simple mistakes. I thought I could as least make 580-600 on the real thing. I purchased the OG 10
ed. and it help has help tremendously so far.
Well, you are moving there....
Just make sure you know the basics such as do not leave questions unanswered and that the first 10 questions are usually very important.