multiple devices on same apple id with itunes

I own a iphone 3gs and each of my sons (10 & 7) have a ipod nano i.e. x3 devices. At the moment i have one apple id in my name and have successfully registered each device seperately and given them each their own names. Syncing each device copies the whole of my computers library to each device but what if i want to be selective about what i copy to each device i.e. they may not want to listen to my music and i may not want to listen to theirs? Is the way to do that to select 'manually manage music and videos' and create a specific playlist with each of our names (will it hold video and music and perhaps even games?).