Parentage:
He's the son of Borr and Bestla, and brother of the twins Vili and Ve.
Consorts & Children:
He's the husband of Frigg, though he's also been linked to Freyja and the giantess Jord. He has numerous sons, most notable of whom are Baldr, Bragi, Heimdallr, the blind god Hodr, and Thor.
Notable Stories Involving Him:
He possesses only one eye, having traded the other one for a drink from the Well of Wisdom. Also in his search for wisdom he hung himself from Yggdrasil, the World Tree, for nine days and nights, refusing food and drink the entire time. He presides over the palace of Valhalla, where his messengers, the Valkyries, bring half of the slain warriors of battle, the other half going to Freyja. In Valhalla, the warriors prepare for Ragnarok, the end of the world, when war will break out in Asgard. When Ragnarok does arrive, it is said that Odinn will be killed by the monstrous wolf Fenrir, but then he'll be avenged by his son Vidarr. From one of his many aliases, Woden, we get Wednesday.
Sacred Symbols:
He possesses a spear that never misses, a magical ring that multiplies itself by eight every nine nights, and an eight-legged horse named Sleipnir. He also has two ravens, Huginn and Muninn, to bring him news from Midgard (Earth), and two wolves, Geri and Freki, to whom he gives all his food, choosing instead to drink mead.
Odinn Around the World:
His Greek equivalent is Zeus, though because he ferries souls into the afterlife, he's sometimes compared to the Roman Mercury.
SOURCES: Wikipedia, Encyclopedia Mythica, & The Ultimate Online Resource for Norse Mythology and Religion