For prepping the Math, download the Math review from the GRE site, its all there, sort of like someone saying at the end of the quarter "Prof, whats on the final?" well here the source tells you. GRE Prep download is there too.
Barrons is universially considered the best if you just getting one book (though its not the easiest) for high scores.
Kaplan is good for a quick easy read and you just want a decent score (ignoring people's differing ablities here just to make product comparisons easier)
Get the CD, its worth it, take as many different Computer adaptive tests as you can, and after you take each one ONCE in a test like situation and record the score, keep taking it till you can beat it (not to measure you, but to prep your mind and pysch and chomp at the TOUGH questions)
Now if you want to kick but on the test, go to amazon, buy the big book used (they don't make it anymroe, so its all used), do hundreds of problems, and do this weeks on end untill you feel that you are way over studied. Carefull not to spend time on the deleted sections (its in that book)
For the Vocab, there is no easy way around this other than learning guessing tricks and roots. The frequency hit lists will help SOME, but to get really high scores here (past 700 and closing in on 800) you REALLY do need a very large vocab. Now this takes serious effort to get if you don't already have the vocab.
Thats all I have, now go study!!!