YouTube Channels and Useful Videos
The Silicon Valley Astronomy Lectures
Online Courses and Course Materials
Massachussets Institute of Technology Open Course Ware (MITOCW)
OpenStax College Physics Textbook
Resources for Teachers: Teaching Materials, Lesson Plans and Experiments
Berkely's 'Understanding Science'
Other Resources
Theories of Everything, Mapped: Quanta Magazine
NASA e-book and podcast downloads
Quantum Spot Academy: Entry Level Resources on Modern Physics