It has been awhile, so I want to give another plug (no, I don't get paid to do this) to freelyeducate.com
Need a resource? Check here first. We have used it numerous times since we started homeschooling for the periodic table, games, to learn ASL (American Sign Language), numerous videos and more.
All the resources and links on this site are free. They are for ALL ages. You can sign up and get free updates via email from them.
Another great resource is our Department of Conservation (state level). For Missouri it is located here but you will want to check on all the links and the entire site as well. From this site, and mailings we are received from them we have learned to identify Missouri trees and plants, and have learned about our wildlife and some Missouri history as well. You can also visit a state park and receive lots of brochures and information as well as talk with a park ranger. Many parks also have free hands on programs for kids as well.