How Stuff Works    www.howstuffworks.com            

Thinkquest      http://thinkquest.org/library/index.html 

Wikipedia  www.en.wikipedia.org/wiki/Main_Page

E-Notes          www.e-notes.com 

Chemistry     http://chemistry.about.com  
                          
Biology           http://cellsalive.com

Current Science News  http://www.foxnews.com/scitech/index.html