Train Simulator Sites

Highworth - My first project site with Martin ("Saddletank"), Robin, Mark and others.(MSTS)
UK Trainsim - UK main site (Mainly MSTS)
Train-sim.com - rest of the world :)
webDotWiz - list of just about every train simulator site in the world
Steam4Me - Yuris Australian MSTS site - Where you will find a good set of tutorials and some of my models
UK Branch Lines - Small group of Trainz branch line enthusiasts.

3D Modelling Sites

Amabilis (3D Canvas) - Source of downloads and tutorials
UK Trainsim - UK main site (Mainly MSTS)
3D Canvas Resource - A collation of 3D canvas information

Train Sim and Modelling Forums

UK Trainsim Forums
Amabilis (3D Canvas) Forums
Auran (Trainz, TRS2004) Forums

Historical

My main interests:

Colonel Stephens Museum - The life of the Colonel
SECR - South Eastern And Chatham Railway
SEMG (UK Southern Railways)