See a guide to using the library for teaching, classwork, and research during the coronavirus outbreak: https://guides.library.msstate.edu/coronavirus
The Open Textbook Library (OTL) is managed by the Open Textbook Network at the University of Minnesota. Books published by many open publishers, such as OpenStax, BC Campus, Open SUNY, and more are aggregated in the OTL. Anyone can suggest a title be added to the library, but the book must meet these criteria.
OTL's FAQ: https://open.umn.edu/opentextbooks/faq
Find over 50 complete courses on the Lumen website where you'll also find customizable faculty resources and supplemental materials such as quiz banks, assignments, discussion forums, slide decks, etc.
For delivery of complete courses in Canvas at a low cost to students, contact Lumen Learning directly.