According to the Writer's Almanac, today is Margaret Wise Brown's birthday. Brown began her career as a children's book editor, and she seems to be best known both for her insistence on making books that kids actually could--and would--use: investing in high quality paper and bindings, using bright colors, etc.
Everyone remembers Goodnight Moon--or they should--but my favorite of her books may actually be Wait Till the Moon is Full, illustrated by Garth Williams. "Once upon a time in the dark of the moon there was a little raccoon," it begins, and it goes on to tell the story of a little raccoon who wants to go out at night but must wait...well, you can figure out why. It's a lovely quiet story, not quite as sleepy as Goodnight, Moon, but fun to read (and sing!) to little sleepy ones as well.