The Apollo Lunar Surface Journal: Eric M. Jones and his team have chronicled the moon voyages in beautiful detail. Complete voice transcripts including Real Media sound, an exhaustive series of photographs, plus original NASA press material. The best site, period!
Contact Light: This is a superb personal account of the Apollo program by Kipp Teague. A splendid first person exploration of the Apollo phenomenon, and how we all felt during a shining period of contemporary history. The adjacent Apollo Imagery Archive is the best you'll ever see.
Guide to American Spacecraft: If you're wanting to visit a
specific vehicle, James Gehard's catalog lets you find your
favorite U.S. flight hardware, no matter where in the world it
might have finally landed.
The Apollo Saturn Reference Page: Unrivaled technical detail is what you'll find in John Duncan's notable collection of photographs, documents, diagrams, and plans.
Encyclodpedia Astronautica: If you're wondering about international spacecraft, and the Lunar Kabin (LK) that never landed, then Mark Wade's superb and detailed site will tell you exactly what you want to know.
S/CAT Remembered: Take a trip back to Bethpage, Long Island, New York as the Lunar Module makers at Grumman have some great stories about building the world's first, and so far only, piloted moonship.
Apollo By The Numbers: The official NASA statistical reference (How far, how much, how many, who went...)
Moonport: A History of Apollo Launch Facilities and Operations: Official NASA story of the Kennedy Space Center
National Air and Space Museum: Apollo coverage from the U.S. government archives
Quest: The History of Spaceflight Quarterly (a great magazine)
Florida Today: Great space-oriented daily news
Collect Space: Featuring The Robert Pearlman Collection
The Michael P. Wright Space Collection
The Fisher Space Pen: Everything you wanted to know about the pen that writes in zero gravity
Wild Toys: Who didn't have a thing for Mattel's Man-In-Space? Major Matt Mason inspired a lot of us in 1967!