Goodnight Moon by Margaret Wise Brown, 1947

Where abstract meets concrete. This is a perfect sleepytime book with a lulling, rocking-chair rhythm as the little bunny says goodnight to all the familiar things in his room. Bold and simple illustrations show bunny getting into bed, getting under the covers, each spread taking him closer to sleep; it confronts nighttime fears with a gradual dimming of the lights and wishing goodnight to “nobody” and “noises everywhere.”

This book has been one of my favorites for going on ten years now. I believe we're on our second or third copy? Since board books are edible. A well-deserved classic.

Worth mentioning: there's now a parody by Alex Rex, Goodnight Goon.