PBS
Pbs Learning Media: Relativity and the Cosmos
This illustrated essay from the NOVA Web site introduces the basic concepts of Einstein's General Theory of Relativity and what we know about cosmology as a result.
University of Michigan
University of Michigan: The Big Bang It Sure Was Big!
A detailed examination of "what is known about the Big Bang itself, the age of the universe, and the synthesis of the first atoms."
PBS
Nova: History of the Universe
This interactive timeline provides information on the big bang as well as other major events of universe evolution. It also provides predictions about the universe's future.
Khan Academy
Khan Academy: Quiz: Welcome to the Big History
This quiz tests you on the overarching themes of Big History which links different areas of knowledge into one unified origin story.
Other
Montana State Univ.: Expanding Universe (Lesson Plan)
This site has a lesson plan in which students gather evidence supporting the Big Bang Theory using a balloon model of the expanding universe.