I just finished The Vikings by Niel Oliver and really enjoyed it. So much I didn't know about the Viking peoples as the extent of my knowledge about them was limited to the 20 min of talk that Leif Erikson gets in American high school history class, what I've read about the 9th and 10th century Danes in England and what I've seen in pop culture. It was really cool to learn about them trading with Arabs and Chinese and even playing a role in early Russian history.