Reviving this thread because cardlady linked to it in the other rune thread!
I decided to get a little more serious about runes, so I'm reading Northern Mysteries and Magick: Runes & Feminine Powers by Freya Aswynn, which is quite good (and very serious about the gods and goddesses, as someone mentioned).
And in conjunction, I read this free book about Northern myths: TEUTONIC MYTH AND LEGEND by Donald A. Mackenzie, An Introduction to the Eddas & Sagas, Beowulf, The Nibelungenlied, etc. [1912?].
http://www.sacred-texts.com/neu/tml/index.htm
I got kind of discouraged by the time I got to the end of the book because it had a lot of stories about people who only care about killing people. But the beginning, with creation myths, etc., was very helpful to understand Northern Mysteries.
I should probably get more academic and look for translations of the Eddas, Sagas, etc. But, hey, this book is free!