Artemis Fowl, Artemis Fowl : The Arctic Incident and Artemis Fowl : The Eternity Code – a trilogy worth reading. These stories are full of fairies, goblins, and other races, together with a “Mud Boy” named Artemis Fowl.

He’s a boy genius with a gift for coming up with the most criminal plans. Aimed at older kids, they’re still a good read even if you’re quite a bit older! All 3 can be found in paperback on Amazon – they’re by Eoin Colfer.
Eoin has also written some other books that I haven’t read, and one that I have. The Wish List – a story about a girl who dies and has done an equal amount of good and bad so gets the chance to go back. To say much more would be to spoil it, it’s a good book and worth reading.