This will sound extreme but I find it's both healthy and effective. Get on what I like to call a "farmer's schedule". In other words, keep your window blinds open, your curtains to the side. Even leave the windows open if it's not uncomfortably hot or cold. Wake when the sun comes up (if you have good light the sun is amazingly effective at waking you up), and in the evening, as it starts to get dark, turn off most of your lights and go to bed shortly after total darkness. This works pretty well assuming you work hard at your job and don't just watch soaps at home and collect unemployment. I know it sounds crazy but it is essentially how we were made to operate. Our access to unlimited artificial lighting, 24 hour TV programming, and the endless internet has shifted the time frame of our day.
The reason I suggest this instead of medication is that there really is no long term solution with medication. Sedative-hypnotics like benzodiazepines (Restoril, Valium, Lorazepam, etc..) and some closely related drugs such as Zolpidem (Ambien) and Zaphlon (Sonata) are really only short term solutions and too many people begin to think they'll never sleep if they don't take them after using them for awhile. Abruptly stopping the use of these meds after a moderate time on them and you will experience some withdrawal effects and insomnia worse than before for awhile. It's a road not worth taking if insomnia has been a life long problem (as opposed to insomnia brought on by some temporary stress in your life). I would suggest seeing a sleep specialist if it seriously affects your quality of life.
I really only suggested the farmers schedule because it did wonders for me but it is really impractical to keep up with in today's business world. I went on a 2 week vacation once that essentially involved sleeping outdoors along a river bank every night. The sun would wake me up at about 5, and after it got dark there was really nothing to do as all we had were flashlights and fire so we went to bed both out of boredom and natural fatigue. Doing this for 14 days straight with the light/dark cycle of the earth controlling your own awake/sleep cycle was powerful. I felt unusually good every day, slept like a baby at night, and didn't have any trouble waking or falling asleep. For over a week after that vacation I would spontaneously wake up at around the same time as the sun would come up, maybe 5ish. I spent plenty of time studying the neuroscience behind all this but I was amazed at how powerful those cycles are when they are consistent and induced naturally by the rising and setting sun. So that's my little story I felt like sharing. Now go make an appointment with a sleep specialist.