Income

There are three main ways to earn gold. Citizen tax, Resource city tax and selling your resources.
Citizen tax is determined by your cities population. For example the city of Bochum has 364,000 total poulation and earns me 54 gold per day.
Resource city tax can be applied if you own a resource city. Despite the resource city income showing as /day you only get money when someone builds a mine on your city. For example, if someone builds a mine in your 100 tax city you gain 100 gold and the builder loses 100 gold.
Selling resources is the best money making method. If mines is built at all times you could make ~150,000 gold per week. This is not prefered though. The most popular thing to do is to sell all your uranium, and a big chunk of your food and oil and keep your rare and steel to build your prefered units.
There are some resources that are more valuable then others
Uranium is the most valuable (5 gold per lb uranium).
Rare is the second more valuable (1.8 gold per lb rare).
Steel and oil are the third more valuable (0.5 gold for one lb/barrel steel/oil).
Food is the least expensive (0.4 gold for one lb food).
Uranium is the least used because you can only do nukes with uranium.
All these sell for higher prices on the market. 
Category:Tutorials