The USM Libraries have developed a guide to Open Educational Resources by Subject - check here for links to Open Educational Resources (OERs) in your discipline.
Additionally, there are many repositories for OER content online:
In many ways, the same criteria normally used for selecting a textbook for a course can be applied to OERs as well. The following checklists of criteria may be helpful as you evaluate OERs:
Some OER repositories such as MERLOT and BCcampus OpenEd have clear indications of content that has been peer reviewed. Other repositories such as the Teaching Commons, OpenStax, and OER Commons state the creator(s) of the content and their institutional affiliation(s) so you can assess the quality of the content sources.