Searching for Information on Charles Cross, RAF

Charles Herbert Cross, my maternal grandfather, served in the RAF during WWII. My mother knows very little about his service but she thinks he was flying missions to supply the resistance in France. In any event, I would like to try to learn about more about him but I am not sure where to begin. Are there any easy and inexpensive ways to research members of the RAF? (As I am in the USA, websites are preferable to street addresses, but I shall appreciate both!)

Many thanks!

 

Try RAF 1939-1945 forum. They may be able to provide some help. Any information regarding his rank, squadron, type of aircraft, dates of service etc. would help immensely.

Leslie