If you're looking for a book describing the structure and operations of the German Air Forces in WWI I would recommend one I'm reading at the moment:
"Germany's War in the Air" by General Ernest von Hoeppner (subtitled "The Development and Operations of German Military Aviation in the World War").
It's a fascinating book, going into great detail (but not monotonous) about how the air arms developed, both in command structure and weaponry. It covers all aspects including aircraft (the different types and their changing roles), dirigibles/spotter balloons, anti-aircraft artillery, communications, etc in a logical format, following the war rather than a particular branch at a time. A real eye-opener on how and why things developed the way they did and from an expert, on-the-spot source. Also an interesting glimpse into the thoughts of a Senior officer at the time, it includes many thought provoking comments on how well the Allies (particularly the French!) were perceived to be doing!
A little hard to read in places due to translation/proof reading errors, but very well worth picking up.
Ian