adrianj
Deity
Ahhh. A very common questionwhats a good guide for figuing out the how many farms I should build on a particular city site? I feel like a lot of times I build too many and my city grow too fast. and how fast should I let my city grow?
and how to manage cities with a balance of hammer/coin/food? should I specialize or just do everything?

Answered by more questions.
What is your goal for the game? If heading to space or some late game victory you'll want more commerce to research your way there faster. So then you would specialise more commerce cities. If you want some military victory or need to expand by the sword then you'll want production.
My style for later game victories is this:
When I plant a new city I'll decide right then if it will be specialised for commerce (1) or production (2) - except for one city with many food resources to become the GP Farm (3).
1. commerce city - Most flat tiles should be cottages. Only build enough farms so that you can work all the cottages and maybe have some excess to grow as the happiness limit increases.
2. production city - Mines and later workshops/watermills are the best. Early on in the game where workshops and watermills are pretty poor I tend to farm everything here. The city grows quickly, but once at the happy limit I'll hire some specialists to prevent growth, or at least balance things out with working mines if there are some. Later in the game when workshops (guilds and chemistry techs) and watermills (replaceable parts) are better my workers will come back to the city and pave over as many farms as allows the city to not starve.
3. GP farm - all farms. Most of the time it doesn't even work them because most of the population is assigned as specialists, but occassionally I'll want the city to add a population or two so the farms get used sometimes.
It's all about specialisation. Deciding a city's specialisation early also helps to focus what buildings you build there. The most efficient empire won't put every building in every city. Eg, a forge doesn't give much benefit to a commerce city. A University doesn't really help a production city. If you run out of things to build, don't just build something because there is nothing else, because there is always something else: wealth.
There must be a few articles in the civfanatics War Academy about this topic.
NB - These apply to BtS and Warlords. Things are slightly difference for Vanilla Civ. Wealth isn't as powerful, hence production cities aren't so useful. For Vanilla I'll probably go with a higher mix of commerce cities.