Here are some OER resources and repositories

Open Resource Workshop - Canvas course with information about how to create an OER composition course from Matthew Bloom (SCC).
Community College Consortium for Open Educational Resources (CCCOER) - Excellent starting point with information about how to learn about OER and find OER. There is also an archive with webinars on many OER topics.
Library Resources Available in the Maricopa Community College District - These resources are licensed for use by MCCCD employees and students.
OpenStax College - OpenStax only has peer-reviewed textbooks that are being used in over 300 educational institutions.
openstax CNX - Free educational material in small modules that can be organized as courses, books, reports or other academic assignments.
College Open Textbooks - This site contains links to a large amount of open textbooks organized by subject area.
Open Course Library - This site has an alphabetical list of courses as well as a how-to guide for using the resources.
Lumen Learning - This site has more than a dozen open courses.
BCcampus - Approximately 140 open textbooks and ancillary materials available to adopt and/or adapt.
Creative Commons - This organization provides a way to let users know how they are allowed use the content they are viewing by providing several licenses that are very easy to select and apply to your materials. Search for images and more.
Merlot - A free and open peer reviewed collection of online teaching and learning materials and faculty-developed services
OER Commons - Curated collections of Open Educational Resources
PHET - Free interactive simulations for physics and math
Sounds - SoundCloud and Jamendo
Open on Demand @SDCCD - Open educational resources at the San Diego Community College District.