A Wizard From Earthsea, by Ursula K. Le Guin, who wrote a series
of books based on the fantasy place of Earthsea. Other titles
included in the series are (In order):
A Wizard of Earthsea
The Tombs of Atuan
The Farthest Shore
Tehanu
Tales From Earthsea
The Other Wind
Studio Ghibli's adaption of Tales From Earthsea is loosely based
on the first books of this series.