OER COMMONS (http://www.oercommons.org/)
Open Educational Resources (OER) was created to provide educators around the world with free K-12 lessons, college courses, videos, graphics, and media to use in the classroom. Just register for free and start searching. OER Commons has established partnerships with more than 100 reputable institutions such as MIT, Yale University, Harvard, Johns Hopkins, NASA to provide you with the highest quality courseware available.