The Mythology of the Norse Gods includes a pantheon of characters and a universe of nine worlds. Our knowledge of these legends comes from the Poetic Edda and the Prose Edda, both of which were written and compiled in Iceland. The Poetic Edda verses do not have identifiable authors. The Prose Edda was compiled by an Icelander name Snorri Sturluson. (Really!) Both date from the 13th Century.
Translations of these stories can be a bit sensitive. For the Prose Edda, consider Edda (Everyman’s Library). Purists seem to like a version of the Poetic Edda written by Henry Bellows in 1936 that is only available online at http://www.sacred-texts.com/neu/poe/poe26.htm. Alternatively, a recent translation is The Poetic Edda (Oxford World’s Classics). For an abridged version, try Norse Stories: Retold From The Eddas…, which is a reprint of a text by Hamilton Mabie, compiled in 1882.
According to the Eddas, the primary family of gods, the Aesir, are led by Odin, the wisest of all the gods. His first lieutenant, Thor, is the strongest, if not so wise, of the gods. There are many other gods and goddesses, all with different strengths and attributes. The other family of Gods is the Vanir. Other beings in the universe include light elves, humans, giants, dark elves, the slain Vikings, animals, dwarves, demons, fire giants and the rest of the dead.
They live in a universe of three layers. The top layer is Asgard, with Yggdrasil, the tree of Life. The Aesir live here, along with the light elves and the slain Vikings. Humans, giants, dark elves, animals and dwarves live in Midgard. Demons, fire giants and the dead live in Niflheim. Harry Potter fans will note the source of the evil werewolf character, Fenrir Greyback, is derived from the evil Norse wolf god, Fenrir.
All of the inhabitants of this universe are awaiting the call to the “Ragnarok” which is the last battle and the end of the world as we know it. The Aesir gods will battle the giants, with everyone else taking sides. Most will be killed. A new, beautiful world will rise and be re-populated.
Marvel Comics and Disney have a very entertaining movie called Thor: Ragnarok that has nothing to do with the actual Norse myths. But, it is fun to watch.