AAMC: MedEdPortal

A service of the Association of American Medical Colleges, MedEdPORTAL is an evolving resource, educators and students from around the world are encouraged to explore free peer-reviewed materials. 

Connexions

A place to view and share educational material made of small knowledge chunks called modules that can be organized as courses, books, reports, etc.

Merlot 

 Multimedia Education Resource for Learning and Online Teaching (MERLOT) provides peer-reviewed onlinr teaching and learning materials. 

MIT Open Courseware

MIT OpenCourseWare. In its ongoing commitment to advancing education and discovery through knowledge open to everyone, Massachusetts Institute of Technology (MIT) OpenCourseWare provides free lecture notes, exams and other resources from over 1,800 courses from MIT's entire curriculum.

Khan Academy

An extensive video library, practice exercises and assessment for K-12 math, biology, chemistry and physics and some finance and history.