Just finished reading David K. Randall's new book called 'Dreamland: Adventures in the Strange Science of Sleep'. It was superb. The book takes a look at the science behind pretty well every facet of sleep you can think of from sleep deprivation, to natural sleep patterns (and how it changes over the course of a lifetime), to putting your kids to bed, to dreaming, to sleepwalking (and the bizarre phenomenon of committing crime while sleepwalking), to insomnia, to just plain getting a better night's sleep. Fascinating stuff. I've written an executive summary of the book available at newbooksinbrief.wordpress.com
Cheers,
Aaron