How many cottages and barracks in evony?

This depends upon which alliance you join, and how warlike they are. If you are in a war alliance, 15-18 barracks per city is fairly common. Otherwise, 12 is good. It cracks me up with alliances who don't stress the importance of barracks.. there are a LOT of cities with 1-2 barracks out there! More food for me... ;)