ROAD/RAIL :
Miniature & miscellaneous railway web-sites - Under 15" gauge
Main UK web-sites - Over 15"gauge

Ploughmans Dobwalls Railroad - 7 ^1/4" You wondered where all those lovely engines went didn't you?
Railway Register - Almost 4000 sites broken down by group.
World Rail & Others - Direct from the Live Steaming, USA.
Steam Locomotive Simulator - Download the software and drive.
Amalgamated Miniature Traction Engine Club
Corris Hill Railway - Members 5" gauge, includes turntable plans, driving truck plans etc.