The Norsemen is a comprehensive & copiously illustrated account of Viking history & civilization with 152 illustrations, maps, charts, bibliography, geographical & biographical index.
As an introduction to Norse culture and achievements during the 'dark' and early middle ages this will serve well. It's dated, yes, having been written in the fifties, and it's a translation, having been first published in German, but the author, a Swede, was a hands-on authority, and the translator did a really good job in producing a readable text.
Although this is an old book in a fast moving field it is worth reading to have a well rounded understanding of the viking era. They were pretty amazing in the amount of the world they explored and the impact they had for a couple hundred years.