Photoclubalpha

1)In manual mode, the manual says:"when the shutter button pressed half way down, the distance at which the proper exposure is obtained appears on the LCD panel. Now what does the following mean? " Set the aperture to match the displayed distance to the shooting distance." To adjust what aperture? On the camera?
2) "The power level range eg. 1/1 -1/2 corresponds to the aperture range, f4-5.6" What does that mean?

If you know the power of your flash (expressed as a guide number), the ISO of the film/sensor and the flash to subject distance then you can calculate an aperture to use.

You can find one explanation here.