Insomnia runs in my family. The solution that works for me is audiobooks. I actually wear earphones attached to an iPod to bed! When I do this, I can almost always fall asleep within 20 minutes or so. It also helps me not wake up if dh happens to start snoring.
Edit: I should add that I also used Tylenol PM every night for a long time (years), but got worried about the long-term effects. Also tried OTC sleep aids. They worked sometimes, not others, and tended to leave me groggy in the morning. I do have a muscle relaxant (prescribed for back pain) that I will occasionally use to "reset" my sleep pattern when it gets way out-of-whack. Only need that two or three times a year.
I found for myself that it was critical that I get into an established pattern of falling asleep quickly once I got to bed. The Tylenol PM helped with this, and now the audiobooks are enough.