The Sea of Monsters. Percy Jackson and the Olympians #2 - Rick Riordan

The Sea of Monsters is the 2nd book in the Percy Jackson and the Olympians Series. You can't tell by looking at me that my dad is Poseidon, God of the Sea. It's not easy being a half-blood these days. Even a simple game of dodgeball becomes a death match against an ugly gang of cannibal giants - and that was only the beginning. Now Camp Half-Blood is under attack and, unless I can get my hands of the Golden Fleece, the whole camp will be invaded by monsters. Big ones...