The Earthsea Quartet

The Earthsea Quartet - Ursula K. Le Guin Contains the four books of the Earthsea cycle.
A Wizard of Earthsea / The Tombs of Atuan / The Farthest Shore / Tehanu

I've got a soft spot for the first book. We were made to read it at high school, and compared to everything else we'd read that year, it was a breath of fresh air. I'd read it at home on my own time, really getting into it.

Duny, also called Sparrowhawk, shows some aptitude with magic and is taken on as an apprentice to one of the greats. Wanting to know more, he heads to the wizard's school on Roke Island.
His pride and anger get the better of him, as he releases a shadow into the world.
His quest to rectify this leads to him becoming more patient, wiser and a dragonlord.

The other books follow on from this, introducing new characters and evolving as the story progresses through them.
The second book is well enough done, but not as good as the first and third.
The final story is the weakest one, written 20 years later according to the copyrights at the start, and seems to be a way of wrapping things up.

Worth getting to have all four books together.