I ordered this because I didn't know much about it. I haven't quite finished it yet, but I'm finding it very interesting. The subtitle is "The Troubled German-Finnish Coalition in World War II", and pretty well sums it up. This is definitely not the view from the foxhole and may not be everyone's cup of tea. The author, Henrik Lunde, was a top man at the Army War College, and he focuses on command decisions (and confusion), and political, diplomatic and strategic considerations. Military actions are covered in detail and supported by excellent maps and photos.
Finland lost some territory to Russia during the Winter War of 1939-40 and quite naturally turned to Germany for assistance. Staff talks were occurring even before the German invasion of Russia, but there was no action until a few days after the launch of Barbarossa, so that Finland could claim that they were "co-belligerents", not "allies" with Germany (there is a difference). Troops from both nations served under officers from both in Northern, Central and Southern groups - only the Southerners had much success and that was pretty temporary. It would be tempting to say Hitler f***ed another one up but there is a lot more to it than that. If Germany lost Norway it would cost her Swedish iron ore and Finnish nickel, which were absolutely critical, so they never really sent enough soldiers. The nations' war aims were not well-aligned, neither side was very honest with the other and the German High Command didn't consider the front very important. Russia was worried about Murmansk and the railway and managed to mount a pretty strong defense. The Finns steadfastly refused to assist in the siege of Leningrad, which was practically on their doorstep.
The Finns were excellent soldiers, good at fighting in cold weather and the heavily-forested terrain they knew well, while some German units appear to have been pretty sorry. SS Division Nord, for instance, was made up of older men with very little training. It was hard to find a German general willing to command them. First time in battle they broke and ran. A few days later the same thing happened, with some units fleeing a full 50 kilometers to the rear, where they urged sentries to blow the bridge, convinced Russian tanks were in hot pursuit. An effort was made to send them home, but Hitler must have only seen them as a push pin on a wall map and kept them where they were. The unit was eventually broken up and parceled out as replacements.