City of Bones by Cassandra Clare
From the back cover: “When Clary Fray heads out to the Pandemonium Club in New York City, she hardly expects to witness a murder. Much less a murder committed by three teenagers covered with odd markings. This is Clary’s first meeting with the Shadowhunters, warriors dedicated to ridding the earth of demons–and keeping the odd werewolves and vampires in line. It’s also her first meeting with gorgeous, golden-haired Jace.”
Because she can see the Shadowhunters, she become a person of interest to them. No mundane, no normal person, has ever been part of their world. Why can Clary see them when no one else can? If you liked The Twilight Saga, The Maze Runner Trilogy, or The Hunger Games, The Mortal Instruments trilogy might be for you.