US Environmental Protection Agency
Epa: Mercury
This site provides a user navigated slide show with animations providing basic information about the element Mercury.
US Environmental Protection Agency
Epa: Learn the Issues: Health & Safety
This site provides real-world issues as well as the scientific research and technology used to support the EPA's mission to protect human health and safeguard the natural environment.
Other
Web ref.org: Mercury
A nice concise summary of basic information on mercury, including sources, history and uses, as well as information on mercury poisoning.