I wil take the test on same day as you.
It is interesting to note that my problem lies in just the opposite as you are. i will share some tips on math and hopely you can give me some tips on verbal section. will you?
GMAT math is actually not too difficult. I received 48 twice in the past two exams. all the concepts are pretty basic. what makes gmat math hard it that smart ETS designed the question in a way that the questions are just damn time consuming and tricky.
i would not bother with kaplan
or any other books other than OG and powerprep. use only materials published by ETS . They are very similiar to what you will see on an actual exam. that being said,
there are several mathematical concepts which showed up on the test very frequently. they are namely: inequality, probabaility , speed/distance problem, simple geometry problems(square, triangle etc). YOu must know the formular inside and out. second, aformentioned concepts are key determiner of how high you will score on the test. if you see questions related to , for example, probability, then you are doing very well. and you must get this question right.
moreover, try to get used to computer screen. do several powerprep sessions and learn your mistakes. it is very important for your eyes to feel comfortable with computer screen. for myself, i have done several practice test using powerprep. that is all i have done for the math part and i got 48.
lastly, you want to spend extra minutes on first 10 questions. they are very very very important. i can not stress this enough. if you messed up on first few questions, it is hard to recover,though not impossible.
hope this helps a bit. Again, stick with powerprep adn learn basic formulars and as alwayson the lookout for shortcut and traps/tricks.
If question is damn long, then there must be a shortcut. once you notice this, your score will go up in no time.