Hi Folks,
After lot of searches, I thought of writing this article mainly dedicated to students. I have included links of sites providing content for students relevant to their studies. And I request you to suggest me more links. So here I begin(just click on the images):
Wikipedia.org
Answers.com
Proprofs.com
About.com
How Stuff Works.com
Tell Me How To.net
Britannica
Access Science.com
Noble Mind.com
Wolfram.com
Encarta
Asme.org
FactMonster.com
Awesome Library.org
Home Work Spot.com
UEN.org
RefDesk.com
Class Brain.com
BBC School
Discovery Education.com
BBC School Guru
Infoplease.com
Students Questions.com
I would be adding more links soon. 
