Nature has a special supplement, freely available online, on the cognitive neuroscience of sleep.
Homer Simpson, who once said “There is a time for many words, and there is also a time for sleep”, would, I’m sure, approve.
The supplement contains a number of articles summarising recent research in the world of sleep, including the types and causes of sleep disorders and the role of memory in producing dreams to name but a few.
Link to Nature supplement on sleep.
Mind Hacks 
I believe it was actually Homer (the classical poet and rhapsode, not the modern-day animated philosopher) who authored the quote you gave.
Fascinating article!