A few good sites to track pending and current legislation are described below:
NOTE: One important piece of legislation to stay abreast of is Publishers v. Georgia State University (Cambridge University Press, et al. v. Becker, et al., Civ. Action No. 1:o8-CV-1425-ODE.) concerning fair use and copyright infringement. The Syracuse University link provides a decision summary of the court ruling.
Copyright Act - Federal law on copyrights is codified in Title 17 of the United States Code.
Digital Millennium Copyright Act (DMCA) - A summary of the DMCA provided by U.S. Copyright Office. The DMCA is an amendment to the Copyright Act of 1976.