AOL@School

http://www.aolatschool.com/ provides educator-reviewed classroom resources for K-12 students and teachers in math, science, language arts, social studies and more. Here you can quickly find activities, research materials, educational games, multimedia resources and lesson plans for primary, elementary, middle school and high school classes.

This site takes a little getting used to but it is loaded with helpfully lesson plans and resources. It can get you started with many web based activities. It contains printable worksheets for students participating in the activities and lesson plans for the teachers. It also has many relevant education related links.