You are the mayor. That means that in addition to building the city, you also must run the city. You will do this predominately from your town/city hall -- though there are times where random citizens will simply step out of their house and send up a thought bubble to trick you into setting off fireworks that burn down whole blocks of factories.
Here's what the government and politics HUD has to say about maintaining happiness among your people:
- City hall allows you to set tax rates
- Each city hall upgrade grants you a choice of one department module
- Many city hall modules grant access to buildings in other HUDs for all cities in the region
- Government buildings increase nearby land value
- Buildings start as low-density but can grow if they are kept happy/profitable
- A building can only grow if the road it is on is big enough to permit the traffic
- Click on an industrial building to see its progress toward the next density level
- Density is the building's size. Land value relates to its wealth level
- If a building loses happiness/profit, it will eventually go abandoned
- An abandoned building may revive if its problems are resolved
Life in Town Hall
Life in a small town is very simple. People want the basics: a good education, a place to go when they're sick, some water to take a shower, and -- if you have some time -- maybe a fire department. As it turns out, the first people who move to your new city are usually people too stupid to live in their home towns and they have a tendency to set themselves on fire.
However, as the quality of your city improves and your population starts to boom, you're going to need some more impressive chops. You'll get specific requests from people like can I throw a mega-party (increases garbage) or bets from people who don't think you can get 100 people to go to the park. You can decline or ignore these requests, of course, but some of them can get you some nice bonus cash to help you develop your city.
Noodling with your tax rates should be a measure of last resort. When you start the game, the taxes for RCI are set at 9%/9%/9%. Don't touch them. Increasing them will only give you angina and decreasing them will cut your legs out from under you even if it makes your people happy.
Happiness and Prosperity
The density of your buildings increases based on how long the residents of that building are kept happy. If you want a city packed to the sky with people, it's about longevity and keeping a steady stream of services to all of your neighborhoods. Keep a good eye on your crime and fire maps, as these are the two maps that can instantly effect population density and land values.