Basically get to Euston, tube to Waterloo train to Brentford (about 40min) its a 5-10min walk from the station once at Brentford pub on each corner of the ground and there is terracing behind the goal. There moving to a new staduim in the next couple of years which will proberly kill what is at the moment my favourate away trip in this league.
There is a tube station near by cannot remember the name of it but you walk past a dual carriageway.