According to OER Commons, "Open Educational Resources are teaching and learning materials that you may freely use and reuse, without charge. OER often have a Creative Commons or GNU license that state specifically how the material may be used, reused, adapted, and shared."
OER Commons is a top resource - search for resources now on their site.
Questions? Contact your Instruction & Outreach library liaison or the Research Desk - email@example.com or 651-641-8812
Why consider OER textbooks?
From image here: https://bccampus.ca/2012/11/08/proudly-borrowed-from-there/
Before you use an OER textbook...
Thoughts from: Pierce, M. (July 28, 2016). Looking at OER with a Critical Eye: Strengthening OER Initiatives by Focusing on Student Learning. Community & Junior College Libraries, 1-7 (request article here).
Electronic textbooks / Interactive mini-lessons and simulations / Full university courses
Who produces Open Textbooks?:
For-profit publishers / Government, university and foundations / Individual authors