I have tried explaining you the things to the best of my knowledge, still if other members reply it would be great.
Some tips:
=> For Toefl prep refer www.testmagic.com , an ultimate resource for preparation. A pool of essays is there, to help u score in essay writing too. I have score a 6.0 in my essay and TestMagic is the one that gets the credit.
=> For GRE, complete the barrons list atleast 2-3 times. Try doing the BIGBOOK tests.