theres a lot of things that can help with sleeping, for example as was said, exercise in the day is good, theres also things like making sure you are totally in the dark, no illuminated clocks or lights from the computer, you can try putting lavender oils on your pillow, lavender is meant to be great at aiding sleep, you may also be able to find a stuffed animal type thing which you put in the microwave before bed, sleep with it and its filled with lavender so the smell comes out, theres the classics like a mug of warm milk no fizzy drinks or caffine, make sure your rooms got pleantly of air (without being too cold) and try listening to soft, calming music, the only other thing i can think of is to keep you bed for sleeping, by this i mean dont sit in bed while you watch TV or read, you shouldnt be in bed unless youre trying to fall asleep
if you look online for info on insomnia (i know you dont have this but the aim of the sites is to get people to sleep no matter the reason) you can find loads more stuff that could help
hope thats some help