So, I, uh, I find I am writing vampire fiction, and as such I am covering a number of time periods: 13th century Baghdad, Cairo between roughly 1450 and 1620, Kolkata in 1811, and Cairo again during the Second World War and immediately after.
I dont know how far along you might be in your research, but if you want info on medieval Baghdad check out a book called Baghdad During the Abbasid Caliphate by Guy LeStrange. It's an older book but amazingly detailed in it's descriptions of medieval Baghdad. Of course the 13th century is also when it all pretty much ended for Baghdad, so if your story is set in the later part of the century a lot of this info might no longer apply.
I have been writing in the early medieval (5th - 11th centuries) for a long time, but I'm branching out to the 16th century for my WIP. It's such a different experience! There are primary sources about daily life! I don't have to cull archaeological journals for everything! I can have characters communicate information via writing!