I recently finished reading John Haywood’s Viking: The Norse Warrior’s [Unofficial] Manual and highly recommend it. The author covers basic details such as why a Norseman would choose to be a Viking in the first place, the various social levels in Viking times, weapons and tactics and the various types of Viking ships.
I like the way Haywood packs in a lot of historical information about life as a Viking and manages to do this without ever being stuffy. The whole book is written in a friendly tone that comes across more as a talk between friends than a lecture or lesson. There is a nice sections that breaks down the different countries of the world and describes them in terms of how hard it was to raid them and what kind of spoils you could expect to plunder there.
There are a good number of period illustrations scattered throughout the text along with some color photos of a modern combat reenactment group demonstrating some fighting techniques. While the book delivers a ton of information it also lists sources for further reading. John Haywood definitely has the pedigree to write an authoritative book on this time period. With Viking: The Norse Warrior’s [Unofficial] Manual he has written abook that is also entertaining.