In A Wizard of Earthsea young goatherd Ged discovers his talent for magic and is sent to the school for wizards on the island of Roke, at the centre of the world. There his pride leads him to folly, and the loosing of a terrible evil on the world. His attempts to escape that will bring him to confront dragons and one of the old powers of the Earth, before an epic chase takes him right to the edge of the world.
Chosen at age five to be the new One Priestess of the Nameless Ones, Tenar is stripped of her name, becoming Arha, the Eaten One. she is the nominal suzerain of a tomb complex. When, in The Tombs of Atuan, she discovers an intruder in the forbidden labyrinth that is her domain, she chooses to turn her back on everything familiar, in exchange for an uncertain future.
In The Farthest Shore something is leaching the wizardry out of the world, and the joy. Arren, the young prince of Enlad, joins Ged on a quest to find the source of the evil. Their search will take them to sojourn with the raft people on the open sea, then across the wall into the dry land of the dead.
Earthsea is a superb exercise in world-building. The novels have both depth and detail, but appropriate amounts of both, forming an organic part of the story rather than artificial additions. Where many fantasy writers draw on a hodge-podge of material and clearly have only a superficial understanding of their sources, Le Guin has a wide and deep knowledge of myth, language, and history. She has dug selectively and worked her material wisely, making something genuinely original — and if parts of her work seem exposed thirty years on, that is only because later writers have carried out indiscriminate open-cut mining in the area.
A Taoist conception of "Balance" underlies Earthsea: the use of magic is dangerous, and can destabilise the natural order. And there are many patterns and parallels in the trilogy. A Wizard of Earthsea is about a young man's coming of age, in which he attends an all-male school for wizards, and much of it is set at sea; The Tombs of Atuan is a young woman's coming of age in an all-female temple complex, and much of it happens underground. And so forth. None of this is explicit, however, nor is conscious understanding of it at all necessary for appreciation of the novels. They are, first and foremost, spellbinding stories, with memorable characters.
There are now sequels to the Earthsea trilogy. Fifteen years later Le Guin wrote Tehanu, which is often coupled with these three novels to form an Earthsea "Quartet". Tehanu is different in many ways, however — it is not a children's book, for one thing — and I consider its inclusion in one volume with the trilogy to be misguided. More recently has come The Other Wind and a book of short stories, Tales From Earthsea.
I would not normally have considered reviewing the Earthsea books: they have received plenty of academic criticism and have been set texts in schools, so they should need no promotion. (Though the cynical might argue quite the opposite.) I keep running into people, however, who rave about Harry Potter and claim to be fantasy fanatics, but who haven't heard of Earthsea.