Goodnight Moon by Margaret Wise Brown

This classic children's book follows a young rabbit's bedtime routine, as it says goodnight to everything around: from the red balloon and a pair of mittens, to the kittens, the picture of the cow jumping over the moon, the old lady whispering "hush", and more. The soothing, repetitive text and warm, detailed illustrations create a peaceful, comforting atmosphere that eases children into sleep.

The 549th greatest book of all time