The Tiffany Aching series begins with the delightful The Wee Free Men, when the 9-year old Tiffany first is identified as a witch, meets the Nac Mac Feegle (or "wee free men", a race of tiny blue men in kilts who enjoy drinkin', fightin', and drinkin') and goes head to head with the queen of the fairies to rescue her younger brother, as well as Roland, the son of the local baron. In A Hat Full of Sky, Tiffany is 11. She's left her home on the Chalk to go to the mountains and get formal training as a witch, but a malevolent spirit called a "hiver" has taken up residence in her body and she must outwit it or die. In the third book, Wintersmith, when the 13-year old Tiffany makes the impetuous decision to join in the age-old Morris dance honoring Winter and Summer, she attracts the amorous attention of the Wintersmith and stirs up jealousy in the heart of the real Lady Summer.
In I Shall Wear Midnight Tiffany is 16 and has returned to be the local witch for the people of her beloved Chalk. But all is not well. She has had a falling-out with Roland, whom she had supposed she would marry one day, and he is betrothed to someone else. Furthermore, there is rising sentiment against witches that threatens to break out into the kind of violence that was seen in the past, and whatever is causing it appears to be focused on Tiffany.
Like the previous Tiffany Aching books, this one is filled with Pratchett's trademark intelligent humor spiced with a little bawdiness (courtesy of the Nac Mac Feegle and the delightful old witch Nanny Ogg) and infused with serious social commentary. There is also a bittersweetness to it: Pratchett has been very public about his diagnosis with early-onset Alzheimer's disease, and this book felt like an extended good-bye to many beloved characters from his earlier Discworld books. At any rate, Tiffany Aching is a child no longer, so I suspect it is the last children's book about her.
My introduction to Terry Pratchett was The Wee Free Men, and after that I was hooked. Tiffany is one of the best female characters to come along in a very long time, and I absolutely love Pratchett's take on witchcraft. I highly recommend that you read this series (and then make the leap over to his Discworld books for adults.)
