This build guide was provided to me by one of my VCsCity Build Guide:
In your main city (city 1) you should have:
6 cottages
14 barracks
1 knights hall
1 alchemy lab
1 embassy
1 rally point
1 workshop
1 blacksmith
1 relief station
1 watchtower
1 stable
1 storehouse (you may decide to remove this when you can defend yourself)
No!!! tavern
1 market (you only need 1 if both cities are in the same province.)
TAXES!!! set your tax to 20% if you haven’t received the achievement, then set it to 0 and go to your castle and collect it every two hours.

City 2:
6 cottages
14 barracks
1 knights hall
1 alchemy lab
1 embassy (you can opt to not have this in city 2, as some keep all of their eggs in one basket and only defend one city, resource wise, so it’s up to you.)
1 rally point
1 workshop
1 blacksmith
1 relief station
1 watchtower
1 stable
1 storehouse (this is very important to have in the city you are not defending)
NO!!! tavern
market is depending on whether you are in the same province as city 1 and if you decide to put it here instead of there. I find it’s more helpful to have it in the city you attack from as that’s where all your gold will go when your troops return.