United States Map Game http://www.sheppardsoftware.com/
State bird, State flower, etc. http://www.apples4theteacher.com/usa-states/capitals.html
Fun Brain http://funbrain.com/kidscenter.html
Starfall Reading http://www.starfall.com
Kidzone Fun Facts http://www.kidzone.ws/
Making Learning Fun http://www.makinglearningfun.com/index.html
National Geographic for Kids http://nationalgeographic.com/kids