I myself have suffered from insomnia and it isn't fun. The best thing I do is have yogurt roughly 15 minutes before I go to bed, something in milk products tend to make humans more sleepy.
Or you could try reading before bed, listen to the sounds of rainfall/calming music, not going on the computer and hour before bed or downloading music from Limewire (or whatever you use) that's for people with insomnia. It's a sleeping aid and it makes you picture things, slow down breathing and relax every muscle. If done properly each muscle feels really heavy which is natural. I tend to use this method every night since I cannot sleep without it anymore.