In non-campaign games, you need to click on the resource surrounding your city that looks like a fertile field.  There should be an option to build a farm there.  To put it another way, you don't build farms from a city's build menu.

I must admit that this irritated me, too. I built my city right next to a nice fertile area and... could not build a farm. The city did not show an option for it. Only by accident I found out that I had to click on the farm tile to build a farm. Perhaps the city should add 'Farm' to its options if a farm tile is within range?

Ciao,

Klaus

Nea, it's OK as it is.

I mean I had the same problem after the beta, but after you get used to idea it's falls well into the game logic.

This, to me, is exactly the problem. No where does it say you need to click on it and then click the "build farm" button. I played my first game for over 2 hours wondering why the option to build a farm didn't become available despite my research.

An nice .. um.. manual would have solved it. 

Still, f'ing love the game. But the manual really really stinks fellas.