This is a thread of Open Educational Resources (OER) sites that I find useful. OER includes full courses, textbooks, or any instructional materials associated with teaching and learning. I can't change the tuition and fees of our students, but I can make my course materials free!

@OpenStax has textbooks and chapters from a range of topics that work especially well for undergrad courses (and some for grad courses too). http://Openstax.org 

There is also @OERCommons which has textbooks, but they also offer a *ton* of teaching materials, including sample syllabi, activities, assignments, dataset, and even whole courses.

http://oercommons.org 

@LumenLearning organizes their materials by courses, which includes some common undergrad courses (like American Govt, Stats Concepts, Micro and Macroeconomics, etc.).

http://Lumenlearning.com 

For those teaching poli sci, the website of @ProfBrandle is an awesome source of #OER materials.

https://shawnabrandle.commons.gc.cuny.edu/open-educational-resources-for-political-science/

There is the Open Textbooks Library from @UMNews which has nearly 800 textbooks!
@OpenEd_Network https://open.umn.edu/opentextbooks/ 

@MERLOTorg is a peer-reviewed collection of online teaching and learning materials.

http://merlot.org 

The Open Education Consortium offers an explanation of different terms and search tips, as well as great lists of other #OER repositories!

http://oeconsortium.org/ 

And here are some other accounts to follow for #OER info
@cuny_oer
@cccoer
@OpenEdX
@OpenEduResource

As I find new resources, I will add to this thread!

See note below highlighting the CUNY Academic Works Repository https://academicworks.cuny.edu  and @cuny_oer https://opened.cuny.edu  https://twitter.com/ProfBrandle/status/1292642903756546051?s=19

Wow! Check out this site from @OpenRobert55 with a longgg list of #OER sites, including open textbooks and intl resources. My thread is likely heavy on #socsci, but this seems like a comprehensive list of OER outlets from a wide range of subjects.
https://www.robertschuwer.nl/?page_id=309 

Great point, @sammyelk20! Look at your institution's library to see their #OER efforts. Not only lists of resources and collections, but support ($) as well. Libraries and librarians are THE BEST!!
(Check out the link to the @LibraryUSC OER Library Guide)
https://twitter.com/sammyelk20/status/1292801635584942093?s=19

You can also check out the work of @LearnfulLabs, a growing open platform initiative for Canadian educators and education authors.

#OER

Wowwwww! This site has an amazing repository of #OER collections. Like, imagine this thread times 10 with better descriptions not limited by character counts

https://twitter.com/OpenEduResource/status/1293132931649568768?s=19