If your class is studying earthworms, check out Math Fun with Spirolaterals. Students in both art classes and computer or web-design classes will love this gallery devoted to the finest artistic elements of webdesign, counters, buttons, etc. For graphic art students, MOWA is an incredible resource with many galleries and exhibits. Looking at this artwork shakes preconceptions of what a webpage can be. MOWA Kids is good resource for students who are learning to create patterns.
Stories are available for elementary students.
Lessons include links to teacher notes, and the web resources included in lesson plans are carefully chosen. This site was designed by the USGS, the Department of the Interior and the US Dept of Education so that students can learn and review facts about geography. Time zones, landforms, and water forms are some of the subject areas available. Here is a good sized list of songs for campfires, cartrips, and classrooms. A website contain ing very appropriate activities for letter and number skill building for grades K-1.