My favourite websites relating to space exploration (and mostly to the Apollo program):
The ultimate Apollo hoax debunking website
Despite the misleading title, an anti-hoax website with a very good discussion board
NASA History Division
The gateway to lots of fascinating resources... if only you can find them.
Manned Spaceflight PDF Documents
A better way to find those resources. An absolutely massive collection of scanned documents that go all the way from Mercury to the ISS. The real deal.
The website for the best book ever written on the space program.
Source for highly detailed DVDs focusing on individual missions and on the development of particular pieces of hardware.
JSC Oral Histories
The story of the history of the space race... told by the people who made it. I can't recommend this enough.
As if anything intereresting is going on these days. But sometimes they have good documentaries.