Game interface
Select, point, left-click. There are two basic modes, (M)ove and (A)ttack.

Along the right of the game screen are some displays and controls:

Map The map display shows terrain type (water, marsh, grass). You can move your viewpoint by clicking on it and dragging the grey rectangle. This display also shows explosions, which can be very useful if you are fighting on more than one front simultaneously.
Squads The squad display shows the health and number of units in each of your squads. The small area to the left shows the current formation of your squad, and a more specific indication of each unit's health. The keys 1, 2 and 3 select each squad.
Communications This area shows text messages from the game itself and from your satellite early-warning system.
Controls This display shows the current mode (Attack, Move, Turn) and whether or not 'Formation' mode is switched on. These controls may be activated with the mouse, and can sometimes provide an alternative to using the keyboard.

Play..
Now go to the applet page, wait for the applet to load, then hit 'join game'.