What shutter speed should you use?
If you want to freeze the action, then use a fast shutter speed of 1/500 sec and upwards.
For normal photography here is a quick guide to the slowest shutter speed you should use:
For a rough guide for full frame sensors (professional cameras) use a shutter speed at least as fast as the focal length of the lens. ie if your lens is set to 100mm focal length, use a minimum shutter speed of 1/100sec.
If your cameras has a 2/3 sensor (most amateur and semi pro-cameras), then for 100mm focal length (roughly equivelent to 150mm focal length of a full frame camera) use a minimum of 1/150 sec shutter speed.
If you have any questions about any aspects of photography or camera choice, please email firstname.lastname@example.org and he will try to answer your questions.