Here are some brief instructions to help you get going.
Start New Game
First you will come to Random Map Settings. You can click on the different societies to see how they differ, or you leave it at random and press Ok. Then you come to the Choose Participants screen, press the 'Random' text on the green player to choose your class and then press Ok to start the game.
Playing a Turn
When the world has been created and you can see a map you are ready to play your first turn. The flashing green square tell you where the currently selected commander is located. The white square in the top left with a commander icon on it tells you which commander in the current square is moving. Usually there are two commanders in your start location.
Before you move you should take some troops with you. Press 'Transfer Units' to take command over some troops. The units with a green square on top of them will follow you. The one with a green diamond on him is the current commander, a white diamond indicates that it is another commander.
When you have taken control of a few units you are ready to start exploring. Click on the map to select a square, click on the same place again to move there. Most armies have 3 action points and it requires 1-3 per move depending on the terrain. Once you have move all your commanders, press End Turn to advance to the next turn.
You should try to take control of locations that bring you the resources you need. Usually gold is a good bet, you can get that from villages, towns and mines. When you have about 50 gold you should have enough to recruit more units.
Winning
Make sure to leave some troops at you home base. If you lose all citadel locations (your home is the only one you start with) you are eliminated from the game. You are also eliminated if all your commanders die. Last player standing wins.
The full instructions for the game can be found in the manual for the PC version. Just disregard the keyboard shortcuts, the rules are still the same. You can find the manual on the page below.