GMAT Strategy

Good Morning. I have started self studying for the GMAT and intend on to give the exam by May end. I have OG 11th Edition from which i have started studying and practising questions. I had given my first exam on Princeton Review and got a score of 320 which is extremely low. I am aiming for 720+ and i know i need to wok hard for it.
So please suggest me what other books can i refer to in order to study and work towards my goal.
Also another big question for me is which practice tests do i purchase that i can take during my study period. I mean there are so many like kaplan, barron, PR. How do i know which one would be the best practise exams that would help me reach my aimed score.

Thanks for your reply.

Hi vgupta,
I am currently taking a virtual online course from Manhattan GMAT. They sell all of their math and verbal strategy guides either online or at some of the local bookstores like Border's or Barnes and Noble. I think that you could get them from amazon.com as well. I think that they are worth the money, too. I would also purchase the Official Guide to the GMAT, 11th Edition for practicing problems written by the people who write the GMAT itself. In addition, I would go to mba.com where you can register as a user and get a free download of their own GMATPrep software. That software includes 2 computer adaptive tests and practice problems for all of the content material tested on the GMAT. I would also try to get a copy of the Official Guide to the GMAT, 10th edition. I would try to find any copies of the old, retired GMAT's. mba.com sells sets of 3 old, retired GMAT's for $25 for each set. I would try to use only the kinds of questions and tests that either come from mba.com or other old GMAT's that you might be able to find on this website. Remember that the GMAT is a computer adaptive test. so, the 2 computer adaptive tests from mba.com would be the best bet to get, first.
Greg

hey greg
thanx alot for yor reply. i have already got the two tests from www.mba.com website. But i guess i should save them for the last since they are only two. I was thinking of purchasing the three other paper tests available on the same website. Do u think any other tests is required like kaplan or princeton review or manhattan other than these two plus three from the official mba.com website.
Also i am confused as to which other books to refer. Ofcourse i am using OG 11th Edition as my bible. I do not wish to take a course for gmat because i dont have any time for attending the classes.

Please advice.

Thanks & Regards
Vishist Gupta