Shutter speed controls how long your camera exposes for a picture. A long exposure time is generally used for low light and night photography whilst shorter exposures are best for everyday photography in normal light. If you are taking sports images or pictures of animals or cars then you would need an even quicker shutter speed.
To get sharp images you need to have a Shutter Speed quick enough so that any handshake doesn’t affect the shot. The general rule for the setting to have is normally 1/focal length for full frame cameras and 1/(focal length*1.6) for APS-C cameras. For smaller sensor cameras you may need even fast Shutter Speeds.
eg with a focal length of 60mm…
Full frame: 1/60sec for sharp exposure.
Cropped Sensor: 1/96 for sharp exposure.
Short Shutter Speeds
For Shutter Speeds of 1/15 or slower you would normally need to use a tripod so that your shots are sharp. If you don’t use a tripod you may have handshake resulting in the picture not good focus. Vibration Reduction and Image Stabilisation may help to some extent, but I always think of those as a bonus and prefer to always stick to the rules above.
Medium Shutter Speeds
For Shutter Speeds from 1/30 to around 1/320 you could use these for most every day shots and get sharp images. Remember the rule above for sharp images so the setting you’d need depends on the focal length you are using for your lens. Sometimes you could go faster to guarantee sharp shots as I have done below.
Fast Shutter Speeds
For pictures of sports, fast moving vehicles, animals etc you would generally a faster Shutter Speed. You could use a slower setting and try a panning effect. If you don’t use a fast Shutter Speed when shooting some of the mentioned subjects you would most likely get blurry out of focus shots.
Shutter Priority Mode
A lot of modern cameras now have a shutter priority mode (TV Canon, S Nikon). This allows you to set the Shutter Speed for your camera and then the aperture will be set by the camera when you go to expose for the shot. This would limit your control of depth of field though but is often a good option for ensuring your shots are always sharp. Note if you’re pictures are coming out too dark at the Shutter Speed you pick then you may need a slower setting and if your picture are too light then you may need a faster setting.