Hi

Can anyone help, I am trying to trace some family that I have I know they exist but I have no idea of Names

I know that my grandfather was married once before my grandmother and had 2 children by this marriage. I am hoping to track these to children. The problem is how I go about this. All I know is his name I have no idea of theirs/there mother etc, this is not helped as my grandfather had an extremely common name....

Any ideas on how to start this sear?