Here is a collection of potentially useful sources that I either have used or want to use, and in any case want to save for future reference. Please feel free to make use of them yourself! I hope that these can be of use to someone in expanding the wiki:

• [1]: Contains several PDFs of various Ancient Rome-related topics. The site is in Hungarian but the files are in English.
• Géographie économique et administrative de l'Égypte: Detailed census (?) data of several parts of Lower Egypt (Qalyubia, Dakahlia, Sharqia, and Damietta) in 1902. I don't think it's technically a census but it's got that sort of info.
• Recensement général de l'Égypte: An official but less detailed Egyptian census from 1885; only lists population of settlements but it covers the entire country.
• Matériaux pour servir à la géographie de l'Égypte: Very old French work listing various locations in medieval Egypt. Often not especially detailed but there's a lot here that isn't on Wikipedia yet.
• Triangular Landscapes: Environment, Society, and the State in the Nile Delta Under Roman Rule: Detailed look at the Nile Delta (particularly the Mendesian nome) under Roman Egypt.
• Land Behind Baghdad: A History of Settlement on the Diyala Plains: Detailed study of human settlement and agriculture in the Diyala region in Iraq, including contemporary (1965) and historical (prehistoric-medievalish).
• The Uruk Countryside: The Natural Setting of Urban Societies: Same author as the above and the same general content, but a different region; southern Iraq.
• A Mediterranean Society: Daily Life: Title says it all. A wealth of material here; I've barely even scratched the surface.
• The City and Area of Kish: Extremely detailed book about the site of Kish in Iraq, covering the region around the site over thousands of years.
• Agriculture in Iraq During the 3rd/9th Century: Again, title says it all. Loads of info about medieval Iraqi agriculture as well as rural society and government tax policy.
• Eastern Turkey: An Architectural & Archaeological Survey, Volume III
• Morphological Survey of Hamedan's Toponyms: Contains potentially useful bits on Iranian toponymy. Note that it's in Persian.
• Tabula Imperii Byzantini Bd. 12. Ostthrakien (Eurōpē): It's in German but it has an extremely detailed description of medieval places in eastern Thrace