This article is from the Legal Research FAQ, by Mark Eckenwiler with numerous contributions by others.
The best sources for information on copyright law are the
treatise _Nimmer on Copyright_, and a large number of publications
available from the Copyright Office. These sources, and others, are
covered in detail in part 5 of Terry Carroll's exhaustive and
authoritative Copyright FAQ, regularly posted to misc.legal,
misc.answers, and assorted other newsgroups. In addition to providing
pointers to sources, Terry's FAQ explains U.S. copyright law in
detail, describing its relation to international law and answering
specific common questions about copyright doctrine. Terry's FAQ is
in files /part1 through /part6.