The one that sticks out in my mind most is the one linked below. The book was so poorly written that I think that article conveyed all of the useful information contained in it. I was so looking for an interesting book on the history of German but what I got was the equivalent of a string of Snapple bottle caps telling me what I already knew. I ended up buying heavy books in German on the development of Althochdeutsch to Mittelhochdeutsch and beyond.