Martin Rüther's history of Cologne during WW2:
http://www.amazon.de/K%C3%B6ln-Zweiten- ... 351&sr=1-2
Outstanding - one of the very best biographies of a city I've come across. The first half of the book is an account, year by year, of all aspects of life in the city, the second half is first-hand accounts, diaries, Feldpost and the like.
Absolute bargain at the price.