Seriously mate, I had a problem sleeping for a while, it's not good.

The best thing is to read a book, if you're not a big reader try some of the "young adult" books like Artemis Fowl, Dark Lights Trilogy etc. [even Harry Potter] just as you're in bed.

Reading uses the same part of your brain that dreaming does so it helps get you into the right state for a good nights sleep.