Here are some books you might want to consider looking at:
United States Copyright Office: Library of Congress
This official site for the United States Copyright Office includes general information, official notices, copyright laws, applications and answers to frequently asked questions.
U.S. Copyright Office Forms
Official site for printable and downloadable forms from the Copyright Office. You must have the latest Adobe Acrobat Reader (r) installed on your computer to view and print the forms. Some forms can be filled in and submitted online.
How to Investigate the Copyright Status of a Work
General information about searching copyrights from the Copyright Office. The databases require telnet.
Copyright Clearing Center, Inc.
Formed in 1978, the CCC is the largest licenser of photocopy reproduction rights. The site allows researchers to browse various databases containing U.S. copyrights.
Cornell Copyright Information Center: Copyright Term and the Public Domain in the United States
This table lists copyright terms and when works become part of the public domain.
Authors are given resources to offer licenses to others, as long as the original author receives credit for the creation.
From the American Library Association, a directory of links pertaining to copyright.
University of Texas: Copyright Crash Course
User-friendly copyright tutorial created by the staff at the University of Texas at Austin.