Hi,
thanks a bunch - really appreciate you saying that. When I started out, i was terrible at maths, so I picked the book that I thought explained all teh fundamentals/concepts the easiest. Princeton did that for me. I do remember that princeton shared teh concepts of data sufficiency much much better than kaplan. At the end of the day, as long as you are understanding all the fundamentals clearly I dont think it matters which book you use. However if you are rusty, I would suggest doing as many questions as possible - (thats why I did Princeton, kaplan, and OG (all three books from each - maths, verbal and the main guide). Gave me much needed practise... (Do the OG at the end, as that is the closest to what come on the actual GMAT, and you want the moemntum going at the end).
If you dont have the princeton data sufficiency chapter, I attached it to one of the emails in this post. It should be on page 1 to someone call imfatt. Please download rthat - the data sufficieny concept explained there really helped me get going .....
What I also noticed was that Princeton/GMAT prep tests (1,2) Power Prep tests 1,2 are teh closest that you will come to getting scores similar to what you should expect in the final test. I did the GMAT prep test 1 to see wehre I was. Its a golden test, very valuable for you to write right before the exam also. I wished I hadnt written it earlier, as I remembered a few answers, adn wasnt sure if what I got, reflected my true capability. Try the Princeton test 1 for your diagnostic. You will know where you stand, plus you will not have used up an important test....
do make flash cards, and work on your timing by writign teh time when you start one question on the paper, adn then writing the tiem again before you start the other, tells you precisely how much time you used up - in GMAT approximation in time can be an expensive penalty

. By doing this I was able to get a feel of how far ahead/back I wsas and time myself on the other questions appropriately. No matter what dont leavce any questions, even if you have to randomly guess.
another thing I learned in time is that if you have a very tough question, dont waste too muh time on it, make a best guess and move forward. Worst thing is that you spend ample time adn then get it wrong, brings your entire score down.
Wish you all the very best - I do believe that you if you first analyse your weaknesses, see where you stand, and then create a study plan to hit on those spots, and work hard on it, there is no way you wont ace it - (god helps those who help themselves), he absolutely pitches in at the end, to give you a small push across the finishing line
Looking forward to hearing yoru success story, please feel free to ask me any question any time
-ngufo
People Never Fail ... They just Give Up