SV650.org - SV650 & Gladius 650 Forum - tracing someones ww2 activities

Following on from the remembrance thread......

the past few weeks I have been trying to trace my grandads activities during the second world war. Sadly he passed away about this time in 2009 at the ripe old ages of 93 and like so many veterans he never spoke of what he did. Neither my nan or my dad really know what he did. All I know is he lived in the dagenham or leighton area and signed up from there I presume, he was a sergeant in the first or second wave that climbed the cliffs at Arromanches on dday, went all the way to Berlin, post war army activities included being a fireman on the Rhine as that was his occupation before the war and soon after that he went on to be a dispatch rider in Holland before returning to London.

There is a family tree thing online I found ages ago when when he passed away, no idea who made it, lost the bookmark, spent the other week looking for as I thought it contained his regiment details ect, anyway after finding it again it was apparent it didn't

Does anyone know how to trace these sort of details or that have done it? I have a picture taken of him in he uniform just before he left but its not clear enough to see badges ect apart from the sergeant one