Turn structure and other fundamentals:
Each turn represents one year. You direct city production, research, and military units, and may provide as much detail as you like. More detailed plans may give you bonuses to random rolls, so try to be a bit more in-depth than "three guys mine the hills, and I'm building a library"!
Turns last until everyone has their orders in, or until one week has passed, whichever comes first. If you miss a turn, your civilization will more or less idle.
City basics:
Your city starts with 10,000 people. Each 1000 people generate 1 labor and consume 1 food. Labor points may be used to work the terrain surrounding your city, producing resources, or used in the city to build or staff buildings. The primary resources are food, wood, and stone, along with various ores. Other resources exist, but you won't know about them at the beginning of the game.
Your city is surrounded by 18 tiles of varying terrain types. Rivers and special resources (like ores, luxury foods, or magical reagents) can be fonud in some tiles. Each tile can be fully worked by one labor point, providing the appropriate resources for the terrain type and any upgrades there.
Labor may also be spent on construction (in or out of the city) or on manning buildings.
All resources but food can be easily stored in your city and used later - but they can also be used in the same turn they are produced. Excess food is wasted unless you have a granary or some other way of storing it.
Building types:
Some buildings are made in the city itself, like a smithy, library, or shrine. Some of these have modest staffing requirements and provide a constant benefit. A generic shrine, for instance, raises the city's morale by 1. Others allow new types of labor to be performed in the city. A smithy allows ores to be processed, for instance, and a hall of learning allows labor to be spent on research.
You may also construct terrain upgrades. These generally increase the resource output of the tile they are built in. Plains, for instance, can be irrigated to raise their food output from two to three. Most upgrades are mutually exclusive - you can't build a quarry and irrigation in the same tile - but a few, like watermills, are 'free'.
Morale and population growth:
The attitude of your citizens is very important! The happier your people are, the more immigrants you attract and the faster your population grows. What's more, at very high and low morale, their productivity is affected. Morale ranges from one to ten, with a base of five, and can be adjusted by many factors. The effects of morale are as follows:
Morale:yearly population growth
1:-4%, -30% production
2:-2%, -20% production
3:0, -10% production
4:2%
5:4%
6:5%
7:6%
8:7%, +10% production
9:8%, +10% production
10:10%, +20% production
Some luxury goods can be consumed for morale bonuses. Your population typically consumes 0.1 units of such goods for every 1,000 people, giving a +1 morale bonus. Additional luxury goods of the same type provide no benefit; different types are needed. If you have more than three luxury goods, further bonuses become harder to get; each additional point of morale takes two different resources.
The most common 'luxury' good is clothing, available by refining wool produced by hills. Your people can scrounge for furs and such to keep themselves dressed, but they're happier if they don't have to.
Leaders:
Every civilization has a few citizens with unusual skills and aptitudes. They may be great military leaders, ingenious engineers, wise sages, or any number of other things. Leaders can provide bonuses to appropriate activities - a sage can lead research efforts in your hall of learning to speed your research, for instance. Possibly more important, however, many buildings cannot be built or operated at all unless you have an appropriate leader available. Without a skilled alchemist, for example, you can't build an alchemist's lab, and you won't be able to do much with it if he's busy elsewhere. Other structures only require a leader to be built - building a huge castle requires a skilled engineer, but once it's done he can move on to other things.
Leaders of the same class have the same basic abilities, but each also has their own special ability. You may not initially know what this ability is, however; it must be discovered either by putting the leader in an appropriate situation or through a random event. Alduf the Sage might be a brilliant teacher of magic, giving bonuses to your wizards, but you might not know it if you never put him in charge of a magical college.
Military units:
To create a military unit, you must be able to equip them - typically this means creating weapons at a smithy. Almost all units may be trained in a single turn, and will be ready to move out on your next turn. Initially, you may only train one unit a turn, but there are ways to increase this limit. Military units draw personell from the population of your city. Most units consist of 100 men.
Most units may move a couple hundred miles a turn in known territory - they have a year to do it in, after all! Supplies may be an issue on long journeys, though, so be careful. Also, exploring uncharted territory is much slower. Also, be aware: if you attack another player, your units will not arrive until the next turn at the earliest - this is to give them time to react, not for any in-game reason.
Units have ratings for attack, defense, health, and movement, and many have special abilities. The exact meanings of attack, defense, and health will not be divulged! (Higher is better, though.)