"Organisationsgeschichte der deutschen Heeresartillerie im II. Weltkrieg"
which can be seen as the 'Bible' on topic german artillery in WW2!
More in german on Panzer-Archviv
I am one of those happy ones that received the first test print Volumes
You will find much info about the weapons, the organisation and the distribution. And unit histories, pictures and so on!Much work spent in archives and in tons of NARA Rolls by the author, you can see that on every page!
Only 500 sets will be printed, only avaiable via Uwe himself.
I recommend to put your bet on it as soon as possible!
Jan-Hendrik
thanks Jeff!! 
). Thousands of pages (printed very well, photos of high quality reproduced) on every Heeres-Artillery-Unit that ever existed, down to Battery-Level, even if they existed only a few weeks)!