I actually use music as a sleep aid quite a bit and even have a whole ipod playlist called "Sleepy". I'll just throw out a couple, though.
Most of this soundtrack works for me, but this is my favorite off of there:
( A few more videos/songs under here! ) And no videos for this last one, but these songs are pretty much instant-sleep for me:
www.moodflow.com/
They have EXCELLENT wallpapers too. I always go there to grab backgrounds for work. <3