User made graphics question for FM08 & 09

I was thinking of using some of the time waiting for FM09 to gather together stadium backgrounds to add to the game once I get it.

My last FM was FM2005, so it has been a while - I have made a lot of graphics for EHM since though.

Anyway, my question is - what resolution should background pictures be? I am assuming 1024x768, but I just wan't to be sure.

And which format should they be in - is it PNG like EHM?

Thanks a lot in advance for any help :-)