well, I might have some more to add to this so long as I get on with a bit of reading (
) as the new book davem gave me today,
The Real Middle Earth, by Brian Bates, looks to have a fair bit in it about Viking culture, myth and belief as it was when brought over to British shores. It generally examines Celtic, Saxon and Viking cultures in Britain, not as they appeared in Tolkien (so its not yet another 'source book'), but inspired by his own love of Tolkien to go looking for the kind of things he wrote about in our history. Ronald Hutton recommends it so that means to me it must be good!