Discover ScholarsArchive (ScholarsArchive is BYU’s institutional repository for the scholarly and creative content produced by the University.) The items in ScholarsArchive can be accessed for free.
Try JoVE (Journal of Visualized Experiments) research and science videos (you need to go through the BYU Library to gain access)
Affordable or Open Educational Resources (OER)
There are many resources available, from free or affordable textbooks to other teaching materials, and it can be overwhelming. If you would like assistance, please contact me (Judy Weeks judy_weeks@byu.edu) or you can also contact your subject librarian if you already work with them.