There are a number of articles on this site looking at the various aspects of sleep (both helping to improve it and explaining how everything works); I've listed a few favourites below.
Want more? No problem. If you're looking to improve your own sleep (and you really can - I was an insomniac for a long time, and now enjoy 6-8 hours a night), consider the Better Sleep Nightly newsletter. Absolutely free.
NB : if you're looking for something specific, just take the search box (top of each page) for a run or click the tag 'sleep' on any of the above articles.
And of course, you can always contact me directly. Details here.
Incidentally, if you’d like to discuss any of the stuff above, come and join us on the Straight to the Bar Community over on Google+. Absolutely free.