FYI:  A particularly detailed analysis of Fair Use---especially as it applies to higher education--is at a webpage of UT Austin:

http://copyright.lib.utexas.edu/copypol2.html

The first section defining fair use also contains a paragraph with links to other excellent online resources, including the "Center for Social Media and Washington Law School at American University, whose Fair Use Best Practices statements" are described as having "informed a fresh approach to the subject."