Well, this was a somewhat boring book. No, that's not an insult. The book is supposed to be boring, as it is made with the express intent of – among other things – teaching you about the weapons and armor used in the Scandinavian crusades in the Baltic states. Detailing those utensils of war, and the changes they underwent during that period, can only be kinda dull, especially since you just don't have very many examples of them remaining in nice condition.
Anyway, the book starts with a brief history of the Baltic crusades and continues with the arms-and-armor part – which is interesting if you're inordinately interested in medieval weaponry, but I'm not; I kept wishing for more pictures and less text in this section. Notably, there are pictures, but the format of the book (only 48 pages) leaves little space for the amount of illustrations that would be needed to keep my interest up.
After that, we get a brief look at the tactics and strategies used in the decidedly inhospitable environment that the Baltic states were. There was little chance of living off the land, not a lot of roads, often terrible ground conditions, especially in the spring and fall (at least in the winter, you could move across the frozen lakes and swamps, which was a lot harder in spring...).
Now, tactics and strategy, that I like to read about, so this is my favorite chapter. Basically, it seems the strategy for conquering the Baltics was based on the fewer-in-numbers crusaders taking and building strongholds while gradually pacifying the area surrounding them and raiding into neighboring territory. Then conquer a bit more land, and repeat the process all over again. You couldn't take too much territory at a time, because you had to be able to support the stronghold you established against the attempts to take that territory back.
Eventually, Sweden would establish control over Finland (and eventually lose it in Gustav IV Adolf's idiotic war against Russia) and establish a power base in the Baltic states that served us well in our brief period as an expanding great power.
Well, even if I'm not sufficiently interested in the minutiae of medieval weapons to make this a book for me, I'll recommend it anyway, as it is an Osprey book and you can reasonably trust them to give you good info. Me, however, I need more and better pictures, or more of a narrative, to sustain my interest.
BTW, if you can read Swedish, here's a page on medieval armor and weapons.