Hello Suplex,
I think it would be helpful to know what kind of tools you have at your disposal to map cities or towns. Campaign Cartographer has a City Designer which is quite powerful if you can conquer the steep learning curve. I recently saw a decent automated town creation website (https://watabou.itch.io/medieval-fantasy-city-generator) which pretty much does all the work for you. Though you can't tweak anything you just have to take what you're given and manually hack the image apart if you want to modify it. Or are you just looking for a guide on what resources should be available in a town such as shops, amenities, fortifications, civil structures? Or how the terrain affects the civic building/planning process?
Best wishes, niekell.