Open Referatories:
Referatories are websites that curate collections of OER. These will link you out to downloadable content and files.
Open Repositories:
Open repositories provide free hosting for OER content, and typically offer services that make it easy to find and curate OER on their platform.
Search Engines:
Search tools that examine OER machine readable metadata to return results, for example Creative Commons Search or Google Advanced Search Usage Rights limiters.