Swan Learning Zone
Swan information, swan pictures and a swan themed interactive puzzle.
All About Birds: Trumpeter Swan
This site is by the Cornell Lab of Ornithology and contains a summary page as well as more detailed information about the Trumpeter Swan. Want to know what one sounds like? There's a sound file on this site as well.
Swan facts with links to more specific information about the different types of swans.
This site, by the Wisconsin Department of Natural Resources contains rather extensive information about the Trumpeter Swan including how to join the Trumpeter Swan Society, which is dedicated to restoring the Trumpeter Swan to as much of its former range as possible.