He is the son of Zeus and Hera, and brother of Hebe, Hephaestus, Heracles, Eris ("strife"), and Eileithyia, goddess of childbirth.
Consorts & Children:
Through Aphrodite, he's the father of Eros ("love"), Harmonia ("harmony"), and the twins Phobos ("fear") and Deimos ("dread"), who often accompany him into battle, along with his sister Eris. Aside from Aphrodite, most of the gods despise him, including his own father, possibly because he's known for being bloodthirsty and cruel yet cowardly.
Notable Stories Involving Him:
Hephaestus, having been alerted by Helios of his wife Aphrodite's infidelity, trapped Ares and Aphrodite in an invisible net the craftsman-god had fashioned himself. He then humiliated them by inviting the other gods to witness the compromised couple. Eventually, the lovers were released, and Ares, embarrassed, immediately retreated to Thrace, the place of his birth.
The dog and the vulture are sacred to him, and his attributes are a helmet and spear, which is often bloodstained.
Ares Around the World:
His Roman equivalent is Mars, who, as father of Romulus and Remus, was of greater significance than his Greek counterpart. He also has a Norse counterpart in Tyr, after whom Tuesday is named.
SOURCES: Greek Mythology.com, Mythweb, Encyclopedia Mythica, & Wikipedia