"An award-winning source for standards-based classroom resources in science, technology and engineering, from NOVA and other public television series." A free digital library associated with PBS provides teachers with downloadable video & audio clips that are aligned with education standards. Scientific topics include earth science, geography, life science, etc.
Hippo Campus is a site where students can go for help in subjects ranging from algebra to calculus. Help in physics, psychology and US history is available as well. Some subjects are also offered in Spanish. Teachers can also create a custom Hippo Campus webpage for their classes.
NASA home page has loads of science and technology based information, that is put into a graphical and interactive format. It covers a wide range of topics beyond space related topics.
This FREE website is sponsored by the U.S. Department of Education. Has an excellent repository of teacher resources and tools, offering content in categories like Arts & Music, Health & Physical Education, History & Social Studies, Language Arts, Math and Science. Has drawings available on materials developed by federal museums and archive collections, educational materials developed via federal agencies and programs like the National Science Foundation, as well as selected resources from sites like Scholastic Inc., the Alliance for Climate Education .
The website is sponsored by the United States and it offers many resources to integrate and supplement in your classroom. All subjects are covered on this site.