Yay! Actually, the books are classics, so your local library should have them, if you've got a local library. The order of the series is The Book of Three -> The Black Cauldron -> The Castle of Llyr (my favorite) -> Taran Wanderer -> The High King. They're based in Welsh fantasy, so they're quite different from the typical elves and dwarves and dragons fare we're inundated with these days.