Use your mouse and spacebar..
Spacebar to shoot. Mouse to aim. Move to the right of your in-game screen to shoot right, move your mouse to the left of the game screen to shoot left, same thing goes with the other sides.

Dig:
Hold the key to which side you'll be digging and hold spacebar + key. ;]

Mine: Hold the spacebar.

Mail:
Walk with keys and grab the mail with "A".

To view others:
Right click a player and click on, "View Profile".