are you kidding? the book is obvious for adults, not to read to your child. Anyone who has a child at some point knows the frustration of trying to get a child to sleep after a long day. This book says what a parent is thinking after the countless times during an evening hearing "can i have some water", "i have to go potty", "i hear something in my closet", "i'm too hot", "i'm too cold", etc. Of course you wouldn't say "Go The F*** to Sleep" to your child but be honest, the thought has crossed your mind.
so lighten up and take it for what it is - a joke.