To tackle GRE, the first thing is to know where you are at the moment and then prepare accordinly filling the voids. At first, download POWER PREP CD from ETS-GRE website (or get it from someone who has appeared in GRE; once you register for GRE, ETS will send you POWER PREP CD) and take the first test. Analyze your score and prepare accordinly.
For me, verbal section was really hard nut to break and I had to con about 3000 weird words from Barron's GRE list. So, the only way to get good score in verbal is to improve the vocabulary. Try to be an avid reader, even if you have not been in the past. Be diverse in your readings. This will not only help in writing essays in the analytical section but will also help you in the verbal section.
For Quantitavie section, practice is the key to success. Try as many problems as you can. Try to learn mathematical trics how to tackle the problem quickly. Try to do the computation in the mind than on paper. In my experience, questions are not tough in this section rather they are tricky. It's the time limitation that kills you.
For analytical writing section, you can find all the essay topic at ETS-GRE website. Lots of sample essays are online too. Practice as many essays as you can or at least plan for all the perspective essay topic before the exam.
The trick: It's absolutely essential that you get first few answers(5-6) correct to get a good score. If you get the first few questions wrong, then even if you do better on the latter part, you will not improve your score that much. So, spend little more time in the first few questions. For every questions you make right, the next questions become harder. So, don't worry if you are getting difficult questions; you might as well be making everything right!!
Resouces-
a) GRE preparation material (book and CDs) from : Princeton, Kaplan, Barron's, Cambridge, Peterson.
b) GRE practice materials from ETS-GRE website (www.gre.org)
c) Other online resources -
http://www.number2.com
http://www.testprepreview.com/gre_practice.htm
http://www.testmagic.com/
Note: ETS is launching the revised GRE General Test in the fall of 2007. So, it will be wise to take the test before that date because the most the test materials available at the moment are for the current test pattern.
