NASA
Nasa: Gemini: Stepping Stone to the Moon: 40 Years Later
On the 40th anniversary of the launch of Gemini XII, NASA offers a comprehensive overview of the manned space flight program that was the first to include two-man spacecraft and was designated Gemini in 1962.
Cosmos 4 kids
Cosmos4 Kids: Mercury
A look into NASA's exploration of Mercury. Site includes reference material as well as a video about the Apollo Mission.
Arizona State University
Arizona State University: Space Exploration Resources: March to the Moon
A collection of images and movies from the original Project Mercury space missions, Gemini Project, and Apollo missions of the 1960s.
Other
Gemini Space Craft Instrument Panels
Here is a picture of the Gemini spacecraft instrument panel.