My son is 9yrs and at 8pm he brushes his teeth and can then either read or play his PSP in bed until 8.30pm.

Either DH or I go in at 8.30pm and turn the lights off... and he's always asleep when we check on him around 9pm.

I think the half hour of 'winding down' time in bed at 8pm makes sure he doesn't lie awake for too long.

On the weekends (or in the summer when he's not playing Saturday morning soccer),he usually goes to bed around 10.30pm.. But he does sleep in a little later on the weekends as well.

HTH!