I just Beat The GMAT!

I wrote gmat in Aug 2008 and got 580 (Quant 44, Verb 27). Later on enrolled in Kaplan private tutoring to improve on my verbal skills, worked really hard and even scored 720 in one of Kaplan's Test. Two days
before my GMAT exam on May 30th 2009, i wrote GMATprep1 and prep2 and scored 670 and 680) I was scoring around 35 in Verbal.

On the D-day started off pretty good with Quant but was running out of time for the last 4 questions so guessed all 4 of them. Later on started off well with verbal and continued well till the end unlike Quant.

I couldn't believe myself when i saw the score it was 580 (Quant 48, Verb 23). I still don't understand how did i score so low in verbal when i had prepared so well compared to last time?

I had studied MGMAT SC, CR bible, completed both OG 10th and 11th,
finished Kaplan Course and had improved a lot in verbal as well as math. I am still in shock as i don't understand what could have caused my verbal score to go so low.

I need help from forum to improve upon my overall GMAT score:

Where could i get challenging Quant problems, as i am able to solve the low and middle level with no issues. Where could i get the elementary level books to brush up my basic skills in Math.

Verbal: How do i improve SC, CR and RC?
What's the best way for me to check if i am improving upon SC, RC and CR.

I really want to nail GMAT this time, please help me achieve my goal.

Thanks in advance.

It's not very easy to say which book is the best for hard quant questions. Some say Kaplan's 800 is the best one for that, but Kaplan focuses an straightforward math problems. On test day, I also saw quite a few word problems and such. People tend to recommend Manhattan GMAT tests for their quant "toughness".

As for verbal: I'm sorry to say this, but IMHO Kaplan verbal is not exactly GMAT-styled. It's obvious they've put a lot of effort in developing their content, but for some reason they really can't seem to nail it down. You should go for PowerScore CR Bible and Manhattan GMAT SC guide for those two areas.

RC is... not that often discussed around this forum, because strategies for this section of the GMAT really depend on your very own style. You should try reading some high quality material, like The Economist or smth like that. This should increase your overall understanding of the subjects and your reading speed.

The best of luck with your prep!

Thank-You for the advice.