When selecting course reserve materials for students, US copyright law does need to be followed.
If you reproduce an item or part of an item (ex: a chapter), you do need to judge whether that reproduction is a "fair use" of the material for either criticism, comment, news reporting, teaching, scholarship, or research.
When judging if a reproduction is "fair use," four factors need to be evaluated.
For more information on the "four factors," and for guidelines on evaluating them, please see the "Copyright Resources" links.
According to US Copyright Law, eventually creative works are release to "public domain" and become available for free unlimited use. Many creators also release their work with "Creative Commons" licenses that preemptively release an item for defined use and re-use. Here are some resources that can help with these concepts.