The US Copyright Office webpage has answers to almost any questions. Now there is a very good FAQ section as well, so we don't have to pour through pages of rules and regulations.

If you are not living in the US, the page is still a good source for sorting out the do's and dont's of copyrights because of International Agreements concerning copyright law. There are a few differences from country to country that one must be aware of, however.

http://www.copyright.gov/


--Mac