Books in Discworld Series series

There was an eighth son of an eighth son. He was, quite naturally, a wizard. And there it should have ended. However (for reasons we'd better not go into), he had seven sons. And then he had an eighth son...a wizard squared...a source of magic...a Sourcerer.SOURCERY SEES THE RETURN OF RINCEWIND AND THE LUGGAGE AS THE DISCWORLD FACES ITS GREATEST-AND FUNNIEST-CHALLENGE YET.

The fourth in a series of Discworld novels starring the young witch Tiffany Aching.As the witch of the Chalk, Tiffany Aching performs the distinctly unglamorous work of caring for the needy. But someone—or something—is inciting fear, generating dark thoughts and angry murmurs against witches. Tiffany must find the source of unrest and defeat the evil at its root. Aided by the tiny-but-tough Wee Free Men, Tiffany faces a dire challenge, for if she falls, the whole Chalk falls with her. . . .

The third Discworld novel. They say that a little knowledge is a dangerous thing, but it is not one half so bad as a lot of ignorance. There are some situations where the correct response is to display the sort of ignorance which happily and wilfully flies in the face of the facts. In this case, the birth of a baby girl, born a wizard -- by mistake. Everybody knows that there's no such thing as a female wizard. But now it's gone and happened, there's nothing much anyone can do about it. Let the battle of the sexes begin.