It's all about routine.
You have to get your body used to going to bed at a certain time and used to getting up at a certain time. Oversleeping messes with your inner clock.
Try taking a 30 - 60 min jog 2 hours before bed... then hit the showers for a nice hot one, and finish it off with a book. Something that will calm you down. I don't recommend the computer, for some reason it makes you feel wide awake. (Or atleast it makes me feel awake)
Don't eat before sleep too, you can feel restless.
When all else fails hire a guy named Bubbah to sing you to sleep in his big hairy arms or at the least give you a good knock on the block.