Pawn of Prophecy (Book 1 of The Belgariad) by David Eddings

A fierce dispute among the Gods and the theft of a powerful Orb leaves the World divided into five kingdoms. Young Garion, with his "Aunt Pol" and an elderly man calling himself Wolf --a father and daughter granted near-immortality by one of the Gods -- set out on a complex mission. In the process, as Garion grows into his early teens, he learns to defend himself, grapples with a wild boar, uncovers spies at a king's palace, learns about sorceryand starts to gain a sense of what his own destiny may be.