When you start the player interface, you will see a text box asking you to paste in game XML. To go past this screen, you'll need a saved game, which the game administrator will provide. As the game progresses, the admin will produce a new save for each turn. These turns are stored in text-based XML. To load a game, copy and paste the contents of the turn file into the text box.
Once you've done this, you will be prompted to select which player you are. Once you've done so, you'll be ready to interact with the main screen:
The main screen is divided into several sections, as follows:
1: Main map. Click on tiles to select them for closer inspection. You can scroll this map by clicking on the brown frame.
2: Global buttons. The "Save Game" button produces an XML file containing your orders (more on this later). The "Players", "Resources", and "Orders" buttons brings up the player, resources and orders windows, respectively, which are described in greater detail below.
3: Basic tile information. This section of the screen shows the selected tile, its owner, and its base terrain type. To claim an unowned tile, click on the tile owner text box (which should read "Unclaimed").
4: Tile features. This section indicates the presence of rivers, roads, special resources, and tile improvements. To build a road or an improvement, click on the corresponding boxes.
5: Tile output. This box shows the expected resource output of the selected tile. This is non-interactive.
6: City information. This box shows the tile's population, and, if applicable, the name of any city present. If you want to build a city on a tile you control, click on this text box. Clicking on the box with a city already present brings up the city window (described below).
7: Army information. This box has information on any military units present in the tile, and two buttons to issue orders to your armies. Clicking on the text box brings up the armies window (described below). If you have armies present in the tile, you may order them to move around the map with the "move army" button (and then using the numpad or the on-screen arrow keys to move), and, if you have an army in an enemy's tile, you may use the "conquer" button to take it away.
8: Minimap. It's a minimap, which you are hopefully familiar with. You can click it to recenter the map.
There is little to remark on in the player window. Your total population and free population are important to keep track of, but straightforward. The lists of your cities, units, and armies are similarly self-explanatory.
This window shows your current resource stockpiles, the expected net change, and your expected stockpiles at the begining of next turn.
You can see in the lower right corner that the minimap is overlapping the resources window. This is a bug, and I'm going to fix it.
This window shows all the orders you have given for next turn. You may cancel most orders here, but army reorganization orders cannot be canceled. (This is because doing so is computationally much more difficult than you might expect.) Most reorganization orders can simply be performed in reverse, but if you order a unit or army disbanded and then change your mind, you will have to close the interface, and reload the game, so be careful with those orders.
This window is one of the most important. This is where you order units and buildings to be built. Taking things from the top, you can rename your cities by clicking on the name box, and order your cities to grow or shrink in population with the + and - buttons by the population box.
Next is the list of buildings. Every building in the game (except for a few hidden ones!) is shown here. Select them for more information on what they do and what they cost to build. Buildings in bold are currently present in the selected city, buildings in black can be built, and buildings in grey are currently unavailable because the city is too small or lacks one or more prerequisite buildings. If you want to build a building, select it from the list and click "build building".
Finally, the "raise unit" button brings up a list of units you can build at this city, and lets you select one to build.
Be aware, each city can only perform one action (raise population, lower population, build building, build unit) each turn. You can cancel the current order by clicking on it in the "current order" box.
This window is where you examine and reorganize your armies. Armies are the containers which hold your military units. You can create new empty armies with the "new army" button at any time, but they will automatically disband themselves unless you move at least one unit into them. You may have more than one army in a tile, in which case you can select one from the list of armies. You can also rename your armies by clicking on the army name box.
Armies often contain more than one unit, and the units in an army can be examined separately. After selecting a unit, you can disband it, or move it to another army in the same tile with the appropriate buttons.
After you have examined the game state, decided what you want to do, and issued the appropriate orders, click on the "save game" button on the main screen. This will bring up a text box with XML containing all the orders you have issued. Copy and paste the contents of this box into a post or PM sent to the game's administrator.