I LOVE about.com! for all the information there.
There is a forum on just about everything and loads of information on each topic as well as an e-mail newsletter
which keeps you informed on your topic.
I joined the education and the homeschool forums as well as the distance learning forum. You can subscribe and unsubscribe at any time.
The Homeschool forum at about.com has links to loads of information on each state so that you can do state history or
just learn about a state (or all of them)
There is also a FunDay calendar which has educational activities that your kids will just think are free time!!
I have loved the free resources/samples available to teachers and homeschoolers as well! Just check out the links on the different pages! You'll be lost in the sheer wealth of information.