These commands will control the direction of the spindle.
M03Sn: Set spindle on, forward (top coming, ie ccw, facing spindle)
M04Sn: Set spindle on, reverse (top going, ie cw, facing spindle)
M05: Stop spindle
Speed in rpm is given by the S command.
The correct format is:
M03S2000 (This turns the spindle on, forward, at 2000 RPM)
For Constant Surface Feed see G96.