A collection of links (pathfinder) to sites that provide copyright free images.
Wiki article discusses the four factors in the fair use clause that help reasoning whether your use is fair. Form given for analyzing fair use.
Creative Commons helps you share your knowledge and creativity with the world.
An article in School Library Journal by Joyce K. Valenza about fair use and transformativeness.
A document that helps educators using media literacy concepts and techniques to interpret the copyright doctrine of fair use.
A very clear, concise explanation of fair use, the four factors to be understood, and the fair use analysis.
A video about using creative commons
An article about learning to use creative commons licensed images (the hard way). Includes a very good video clip explaining its use by common craft.