Owners Manual - pages 29 thru 32

Go to page 30 to see Shutter Priority.

Turn Mode Dial to (S) Shutter Priority
Use Command Dial to set shutter speed.

When you change the shutter speed, the camera will automatically set the Aperture to obtain the perfect exposure.
If you are going to photograph motion or action scene, pick a faster shutter speed.
If you select a speed that is too fast, for the available light, the shutter speed on the LCD screen will turn red.