In general, Copyright Law prohibits reproducing and distributing copyrighted works. A simple way to provide access to copyright-protected materials is to link to them, rather than reproduce the content. This works well for materials available in the library databases, as well as works available for free (but not freely licensed) on legitimate websites.
When linking is not possible, the "Fair Use Doctrine" (Section 107) allows a limited amount of copying for purposes such as teaching and scholarship. In determining whether the use made of a work in a particular case is a Fair Use, the factors to be considered include:
This application lets you enter information for title, author, license, organization, and project to help you easily cite open material you find. Use this to cite openly distributed work, such as work licensed by Creative Commons or released in the public domain.
Creative Commons licensing is at the heart of the OER movement. CC allows creators to specify more flexible forms of copyright that allows "others to copy, distribute, and make some uses of their work."