Knowing where to start isn't always easy, especially when you're dealing with an unfamiliar subject. Sometimes the best place to start is a subject specific dictionary or encyclopedia. Below is a list of print and online reference resources for Classical Studies and Art.
Central Library, Reference 4th-flr: NX650 .M9 L494
The LIMC tries to present what we know of the iconography of Greek, Etruscan and Roman mythology as well as of the neighbouring Mediterranean cultures. Each of the illustrated figures of Greek, Etruscan and Roman mythology is discussed in alphabetic order, usually in an individual article of a uniform structure.
Central Library, Oversize 3rd-flr: BL727 .T44 2004