ALA collection of sites for Parents, Teachers and Kids
This site alone has hundreds of sites for all age levels of Learning and Fun and is completely kid friendly!
This site is made specifically for teachers of all age levels, and has MANY worksheets for each learning level!
Storyline Online (childrens audio and visual storiebooks FREE online - read to the children by actors)
http://www.ABCMouse.com/ (this is free in the library)