Datamasters Website.
The home of the OPT Project and the XvT Editor.

The Star Wars Modelling Alliance.
Very good meshes in 3D Studio format and excellent artwork.

The Code Alliance
at Your source for utilities for all sorts of games editing.

The Star Wars Technical Commentaries.
Interesting reading. Has attempts to make sense of the various contradictions as well as gathering the available information in an organised fashion.

Star Wars Space Sim Guide
Contains comparisons of various ships as well as information on the games.
Ace Antilles X-Wing Outpost.
Has various updates and guides for XWA.

The SFA.
Rapidly developing into a great league.

Totally Games Website.
Includes vacancies (we can dream, though perhaps not move to Northern California).

The Dilbert Zone.
It's Dilbert.