MERLOT is the Multimedia Educational Resource for Learning and Online Teaching originally started at Sonoma State University. It’s since become a large group working to provide Open Educational Resources (OER), along with services and research, to the educational community at large.
It’s free to register and use MERLOT. Once registered and signed in, you’ll have the ability to bookmark collections and search the site. The site uses a Smart Search allowing for using different terms and methods of searching, while also finding resources outside of MERLOT itself.
As to the quality of resources, MERLOT employs a peer review process by people who teach in their respective academic disciplines. This creates a significant value in saving time when searching for effective, quality resources.
If you are interested, take a look at MERLOT for your needs.