GMAT Quant and verbal suggestions

My first post here, so I'll give some background. I'm a 28yo engineer in the US. Bored with the technical area, looking to move into finance or (more likely) MC. Looking to apply next year for class of 2009, will attempt GMAT in spring (march/april). Looking for a 750 score.

I just started looking into the GMAT and took the GMATPrep test last week without any studying or even knowing what types of questions to expect. I scored a 700 (Q: 46, V:40, skipped AWA) which is pretty good from what I know. I've always done on standardized tests, not sure why -- I scored a perfect 800 on the quant of the GRE. I must say though, the quant on the GMAT is wayyyy harder than any other test I've taken...I thought all I needed was HIGH SCHOOL MATH!!!

That being said, I'm looking for suggestions on what books I can use to improve my quantitative score. I'm looking for a book that knows what types of math questions are on the test (especially the harder questions in the 45+ quant range) such as probability, Venn diagrams, number properties etc...and shows very well how to tackle these questions. I'm trying to get a 51+ quant score and hopefully keep my verbal score in the same range.

For the verbal, I got Princeton guide...any feedback/suggestions on that would be great as well.
Thanks!