My Area of Expertise: The Ancient Mediterranean.

The Lightning Thief, Rick Riordan
The Sea of Monsters, Rick Riordan
The Titan's Curse, Rick Riordan
Iris, Messenger, Sarah Demming
The Last Girls of Pompeii, Kathryn Lasky
Ithaka, Adele Geras
Troy, Adele Geras 
Nobody's Princess, Esther Friesner
Corydon and the Island of Monsters, Tobias Druitt
Corydon and the Fall of Atlantis, Tobias Druitt
Goddess of Yesterday, Caroline B. Cooney
The Shadow Thieves, Anne Ursu
The Siren Song, Anne Ursu

Other suggestions please?