Bureaucratic Reform in the Ottoman Empire: The Sublime Porte, 1789-1922 by Carter Findley
This is the definitive work on the evolution of the bureacracy of the Sublime Porte, the government offices that contained the Grand Vizierate and the Foreign and Interior Ministries.
While a "must read" for a serious Ottomanist, it's a bit like the verbal equivalent of eating chalk. I have never taken longer to read something.
It is, however, the only English-language text that thoroughly covers the development of the Ottoman bureaucracy in the reform era. It is also extremely expensive; after much searching I found a copy for 90 Br. Pounds. Only recommended for the most serious Ottomanist - otherwise, I would just email someone who's read it for info.
There is a companion volume by the same author, "Ottoman Civil Officialdom: A Social History" which is moe interesting, as it focuses on the actual people who comprised the bureaucracy, and contains much useful data on such things as the percentage of non-Muslims that served (a much greater number than is generally imagined) and the types of people that entered government service. It is also hard to find and expensive, but is recommended reading, as it's much more accessible (and shorter).
