EOL is an attempt to create a complete biodiversity database on the web. It is similar to Wikipedia with a goal of having an entry for every species. Unlike wikipedia the EOL organization vets the contributers and will attempt to maintain the quality of the entries. Currently there are only a few complete entries and over a million entries that need to be filled out, but this will hopefully improve over time.
This is a companion site to the PBS series Evolution. It contains numerous interactive exercises and simulations keyed to the episodes of the show. The Evolution Library has a large number of useful resources indexed by topic. While it is listed as a reference site, it contains animations, simulations, and tutorials as part of the larger site.
Key biological concepts animated as narrated and stepped tutorials, along with quizzes.
The Virtual Cell site contains 20 different animations of cellular and molecular processes aimed at the introductory biology student. Each animation has a flash movie version or a step-by-step walk-through with a voice over explanation. A transcript of the voice over is available. There is a link to a set of Youtube versions of these videos.