The least you need to know to protect your work. Copyrights only protect certain intellectual property. What copyrights mean to you. What you need to do to get the protection you need. Your lifetime, plus 50 years, if the work was created after January 1, 1978.
Work created before that has different rules.
Certain things aren't protected. Be careful, this can get complicated. Well, despite the titillating events in the news last fall, Congress produced some important copyright legislation to meet the needs of our accelerating digital era. In October, the Digital Millennium Copyright Act was signed into law by President Clinton. It tidily meets the needs of both copyright holders and the general public, which wants access to copyrighted materials on the Internet and Web.