Shark Attack -- The PBS series "Nova" explores the danger, mystery, and science of sharks. A transcript of the television broadcast is available online. (Note: The transcript file is large, and may take a few moments to download.)
Shark Week -- This offering from the Discovery Channel Online corresponds with their periodic broadcast of shark related shows. Highlights include: a livecam video of the Giant Ocean Tank exhibit at the New England Aquarium in Boston, and the Shark Tank where you can learn about more than a dozen sharks, from the Great White to the Wobbegong.
The Pelagic Shark Research Foundation -- If you've got the time (or a high-speed Internet connection), you'll want to check out their video library of shark encounters.