BHL provides free access to historical books, images, and resources that are related to science and biodiversity. Items range from public domain to fully copyrighted materials, so note the copyright notices on BHL items.
CASA - the Civil Aviation Safety Authority of Australian - has two playlists focused on human factors issues. One is focused on pilots, and one on engineers.
PhysPort is NSF funded, and focused on research-based pedagogy for physics. The site provides curriculum support, assessments, and resources for effective teaching. Some materials require an account to verify educator status.