The following free sites provide resources for K-12 teachers, as well as for students.
"Extensive collection of digital video materials supporting science, technology, engineering, and mathematics (STEM) education reform." From the Harvard-Smithsonian Center for Astrophyics.
Specifically targeting new teachers, this site is intended to assist classroom teachers with tips and ideas, teaching strategies, recommended books, and more.
Professional development and teaching materials formerly broadcast by Annenberg Media. Provides access to programs in: Arts; Foreign Language; Liteature and Language Arts; Mathematics; Science; Social Studies and History.
Access to over 3,500 free, high-quality educational videos, in such as areas as Sciences, Arts and Humanities, and Social Sciences. Hosted by the University of Washington (Seattle).
Teaches users about the science and history of evolution. Includes a section for K-12 teachers. Developed by the University of California's Museum of Paleontology and the National Center for Science Education.