The Saga of Darren Shan

The saga of Darren Shan is about a 14 year old boy who strikes a deal with Mr Crepsley, an old vampire.  There are 12 books in the series; Cirque de Freak, Vampire's Assistant, Tunnels of Blood, Vampire Mountain, Trials of Death, The Vampire Prince, Hunters of the Dusk, Allies of the Night, Killers of the Dawn, The Lake of Souls, Lord of the Shadows and Sons of Destiny.

They are recommended for 10 year olds and over.  Here is a short paragraph from The Vampire Prince;

He threw one of the knives but I ducked out of the way with ease.  Before he could throw the other or get close enough to stick it into me, the two young wolves launched themselves at him and knocked him to the floor.  They bit and clawed at him, howling with excitement and fury.  He shrieked and tried fighting them off but they were too powerful.  One of the wolves sunk its teeth into the vampire's neck and made a brutal end of him.