He is the son of either Zeus and Hera or just Hera, and brother of Hebe, Heracles, Ares, Eris ("strife"), and Eileithyia, goddess of childbirth.
Notable Stories Involving Him:
He is often depicted as lame, either because he was born that way or because he was tossed from Mt. Olympus one day. As the god of technology, he is said to have built machines to help him in his work, and possibly a wheelchair or chariot to help him get around. As the god of the forge, he's the patron god of blacksmiths and craftsmen, and is responsible for forging various items for mortals and the other gods, such as the bow and arrows used by Eros. In fact, when the sun god Helios informed Hephaestus that his wife Aphrodite was having an affair with Ares, Hephaestus forged an invisible net and trapped the lovers in it, before inviting the rest of the gods to witness the compromised couple.
His attributes are, of course, a blacksmith's hammer, an anvil, and a pair of tongs.
Hephaestus Around the World:
His Roman equivalent is Vulcan, though he's also been identified with the Egyptian Ptah, the Norse Weyland the Smith, the Celtic Goibniu, and the Celtic Gofannon.
SOURCES: Greek Mythology.com, MythWeb, Encyclopedia Mythica, & Wikipedia