Exposure

Set the shutter speed with the shutter speed ring with is at the front side of the ring and the aperture with the aperture ring, at the back side.
Then, charge the shutter with the shutter cocking lever (circled in the left figure).

Self-timer

The self-timer is set by the procedure as follows : After pulling down the shutter cocking lever till it stops, depress the button there to the back.
Then, with depressing that button, again pulling down the shutter cocking lever from there.
The shutter will be released in 12 seconds once the shutter is released.