This is a great little video that teaches the basics of what I teach when I work with people with trouble sleeping, including what constitutes insomnia, what types there are, and how to turn it around.

Some other important tips from me:

1. Be sure your jaw is relaxed when you are trying to go to sleep.

2. Be sure you are comfortable in temperature, bed, sound, light, safety, etc.

3. Remember darkness causes a physiological response that leads to sleep more easily, so sleep in darkness, and spend some time before sleeping in dim light.

4. Do whatever it takes to disconnect from the waking world.  For example, any sounds may capture your attention, even mildly, and cause you to stay connected to the waking world.  Sleeping is about disconnecting from the waking world and entering the sleeping world.

5. One of the best ways I've found to enter the sleeping world is through story.  Think of something pleasant that happened to you, or make up a story, but in either case, begin imagining the story in your head (this is after every other sleep-inducing condition has been completed, and you are prepared to sleep).  Take yourself through the story like you're watching a movie.  I find that getting engaged in that story, takes you out of the waking world, and into the sleeping world.  Generally, before people get far into the story, they are asleep.

6. Be sure to have an hour bedtime routine before the time you want to be asleep.  Do the same things in the same order every night.  Don't look at any screens (tv, computer, video game, etc) during that hour.  Do only relaxing things--hot bath, soft music, dim light, hot caffeine-free, sugar-free tea/beverage, etc.  You will train your body to expect, prepare for, and shift gears into sleep.

7. Only get in bed to sleep, make love, or read something that puts you to sleep (like something complicated and boring, or something soothing--whatever works for you).  Never work, argue, obsess, worry, solve problems, or read something you can't put down because it's so interesting in bed.  If your heart or mind are racing, don't be in bed.  If you feel anxious, do some physiologically-relaxing exercises before getting in bed (such as flexing, holding, and relaxing each muscle area throughout your body, or imagining each part of your body being warm and heavy--as vividly as possible), and some mentally relaxing exercises if needed too. 

8. If you wake up in the middle of the night and can't go right back to sleep, get up and write about what is on your mind (not in bed).  When you're satisfied that you got it all out on paper, put it in a safe place and go back to bed.  Then start with a story again, and if other thoughts intrude, remind yourself that you can deal with that during waking hours (be sure to designate waking hours to deal with the stuff.  Many people put their worries or problem-solving thoughts out of their minds during the day because they are busy, so sleeping time is the only time they get attention.  That is a set-up for not sleeping.  Make space for thinking those thoughts during the day (up to one hour before sleep).  Once you remind yourself of your committment to think about those things during waking hours, take your mind back to the story.  Reading something boring and hard to understand can work here too.