Short answers, pulled from the story.
Odin is widely regarded as a god of the dead and of warfare, who receives slain warriors called the einherjar at Valholl in Asgard. He is also strongly associated with poetry, possession, prophecy, and the runic alphabets. The Prose Edda depicts him as the head of the pantheon, sometimes called the Aesir.
Odin sacrificed one of his eyes in exchange for wisdom. In the poem Voluspa, a volva tells him she knows he has hidden his eye in the spring Mimisbrunnr, from which Mimir drinks mead every morning. He is often described as possessing only one eye as a result.
The English weekday name Wednesday derives from Old English Wodnesdaeg, meaning day of Woden, which was Odin. The term descends from Late Proto-Germanic Wodanesdag and is a calque of the Latin Mercurii dies, day of Mercury, because the Romans identified Odin with Mercury.
More than 170 names are recorded for Odin, making him the god with the most known names among the Germanic peoples. The names describe his attributes, refer to myths involving him, or point to religious practices associated with him. Many derive from the reconstructed Proto-Germanic theonym Wodanaz, meaning lord of frenzy.
In the poem Havamal, Odin recounts hanging on a windy tree for nine nights, wounded with a spear and offered to himself, given no bread or drink. Peering downward, he took up the runes and then fell back. The tree is near universally accepted to be the cosmic tree Yggdrasil.
Odin is killed by the monstrous wolf Fenrir at Ragnarok, where he leads the einherjar into battle. His son Vidarr avenges him by stabbing the wolf in the heart. Depictions of his death appear on objects such as Thorwald's Cross on the Isle of Man, dated by Rundata to 940.