Edred Thorsson broke it up like this. Religion, seidr and shamanism, and galdr and rune work. If you are wanting to learn abou`t the religion I'd start by reading the Poetic Edda. For a jump start on the lore I recommend Myths of the Norsemen by H A Guerber
Poetic Edda link
If you'd like to look into the magical practice of this path I can suggest authors and links to e-books. Magic that relates to the Northern path are rune work, galdr (verbal incantations), and seidr (trance work.)
Authors I suggest:
If you have questions or just want to chat feel free to mail me.