Sigurd is one of the great Norse heroes, and by the name of Siegfried he is also a famous character in Germanic mythology.
Research Tip: You can learn about Sigurd at Wikipedia, along with other characters from his stories, like the god Odin, Fafnir the dragon, and the valkyrie Brunhild. There's also an article on the Wagnerian opera cycle about Siegfried: The Ring of the Nibelung.
You might also enjoy these books: The Story of Siegfried by James Baldwin, Siegfried by Sabine Baring-Gould, Stories of Siegfried by Mary MacGregor, The Fall of the Nibelungs translated by Margaret Armour, The Nibelungenlied translated by Daniel B. Shumway, and Teutonic Myth and Legend by Donald Mackenzie (which features all the main Germanic heroes).
Some Past Projects: