If you get some flash.ocx error, just update to latest flash player or use install_flashplayer10_chrd_aih.
for a first look at scenario crea Train Simulator World, free and safe download.
Built-in tutorials help you get to grips with the controls and different driving techniques. The future of train simulation is here! Train Simulator 2012 puts you right inside the cab, driving incredibly realistic steam, diesel and electric trains on stunning real-world routes in the UK, US and Germany.