On the battle map, place the mouse cursor over an icon to see the tool tip. If the icon has an equivelent hot key, it will show. Most of the icons on top of the screen have hot keys (Group, loose formation, close formation, wedge formation, skirmish, hold formation, engage at will, hold position, fire at will,....).

Check the Options in the main menu. I'm not sure if there is any kind of Control mappimg there.

The Manual lists a some of the hot keys.