Sadly the upheaval of two defeats meant that most of the photographs taken were either scattered or destroyed, especially after the second world war. Although they aren't terribly rare because of this and I own a few, I can't help feeling a little sad they aren't held together for research like the British ones for example.
Anyway, my new website (which is still a while away from completion) has a number of zoomable aerial photos on it - most of them German. Here's a couple to wet your appetite:
http://www.warillustrated.co.uk/aerials.asp?ResID=41
http://www.warillustrated.co.uk/aerials.asp?ResID=28
The first time you try to access one of these pages it will trigger a plugin download, after which it will start downloading the images - you'll gradually see it getting sharper and sharper. Left click to zoom in, right click to zoom out and drag to pan.
Have fun
Finn