The Center for Social Media recently released what it calls a "Code of Best Practices in Fair Use" that, in its words, "clarifies the fair use of copyrighted materials for teaching and learning, putting an end to copyright confusion for educators." That's a bit hyperbolic -- but it is a very interesting, and very well-put-together, document that's both (a) a terrific summary of the law of fair use, and (b) an excellent set of principles, or rules of thumb, to guide those who are using copyrighted material in educational contexts about when they can (or can't) assert that they're making "fair use" of that material.
There's something of a "political" slant to this, it should be noted. The document is, explicitly, trying to arm educators so that they will assert their fair use privileges, more vigorously than they have done in the past, all as part of a campaign to re-invigorate the doctrine. [James Boyle's new book, "The Public Domain" -- which I haven't yet read, but which I suspect (knowing Boyle's other work) is well worth reading and which is on my nightstand -- and Larry Lessig's "Remix" are both part of this movement as well]. Over the last decade or so, probably largely as a result of well-publicized lawsuits by the RIAA and others, lots of institutions, including educational institutions, have become terrified of the prospect of being targeted in a copyright infringement suit, and have adopted policies that are timid (or worse) in regard to the use and re-use of copyrighted material in the classroom or in the general scholarly or educational endeavour, and this little document is designed -- well-designed, imho -- to reverse that trend. Worth a look, if you've ever found yourself concerned about using copyrighted material in your teaching or writing.