A children's picture book written by Margaret Wise Brown, and illustrated by Clement Hurd. First published in 1947, and it's been a crowd-pleaser ever since.

The basic plot is that there is a child (who happens to be a bunny), who is going to sleep. Before doing so, he systematically wishes goodnight to everything in his room, and the moon.

The illustrations alternate between brightly colored full-page pictures of the bunny's room (growing darker and darker as the lights are turned out and the fire dies down), and black and white studies of various items that can be found in that room. The pictures aren't anything special, but they're busy enough to be visually interesting, and they rely heavily on contrast between bright shades of red, yellow, blue, and green, which really catches the eye.

The story is minimalistic, probably averaging about two lines a page. It's done completely in rhyme:

Goodnight room
Goodnight moon
Goodnight cow jumping over the moon
Goodnight light
And the red balloon

About eight pages are devoted to enumerating some of the major points of interest in the room (the picture of the cow jumping over the moon, and the red balloon, for example); the rest is an attempt at an exhaustive list of goodnights. Little kids love it.

When reading this book, remember to look for the mouse. He's in every one of the color pictures, and darn cute, too.