Some Must Watch While Some Sleep helps you learn about yourself and the way you act when you are in dreamland. Each chapter has sections so if you're even looking for one particular thing you can find it right away, or you can be like me and just read the whole book. Also, there's some funny parts every once and awhile which keeps you pushing to the next section.
I read this book at about the same time I read Creative Dreaming by Patricia Garfield. Together, they covered sleep phenomena pretty well for a lay audience.
There are doubtless more up to date books about sleep and sleep research than Dr. Dement's, but it is well written, informative, and humorous.