Wikipeda: Orca (New Window)
This site has a comparison graphic comparing the size or an orca with a human. It also has conservation status, scientific name information and a distribution chart as well as lots of information about orcas.
American Cetacean Society Fact Sheet: Killer Whale (New Window)
Facts about the orca, or killer whale. This site contains a lot of information about physical description and has a graphic of an orca skull.
National Geographic: Orca (New Window)
A nice large picture of an orca opens this site and is followed by an orca whale profile and a comparison graphic comparing the orca with the size of a school bus. The site also includes a printable fact sheet as well as a photo gallery.