Here is a great educational website we recently found. http://www.iknowthat.com  is  for Pre-K through 6th grade.  Topics covered are:

The Arts
Language Arts
Math
Science
Social Studies
Thinking Games

There is also a Teachers Guide.

To play you can pick your grade level and then the topic you want to explore.  There are tons of games and activites to play! The graphics are very high quality.   This is a really impressive site and it's free!  There is advertising on the site and you can join and pay to play without the advertisements.  So far the ads I have seen have been for Vons, Universal Studios & Best Western.  (Although I am not crazy about advertising on children's websites I didn't find these sponsors offensive.)

I can see my daughter and I spending a lot of time on this site in the near future!

Jamin  is the homeschooling Mom of 3 great kids, ages 2, 5 and 11.   She loves homeschooling and finding creative things to do with her kids. She and her husband have been married 17 years.  She is also a Usborne Book Consultant.  You can visit her store at http://www.usborne2u.com