Already two of my articles came up under useful articles. It just means that, aside of many expert photographers, there are enough starter users who recognize those basics valuable.
Now, what is importance of shutter speed. With combination of aperture it directly affects quantity of light that will reach sensor or film. Although, quantity of light could reach the sensor in few different setups. If your correct exposure is f8 with 1/250, then you can catch the same quantity of light with f11 and 1/125. Every f number opens or closes aperture twice. And so every step on shutter speed setting increases or decreases the time of sensor to be exposed (also twice). For example you can walk 10 meters in 10 steps of 1 meter, or in 5 steps of 2 meters, the distance at the end will be the same.
So whats the practical use of this knowledge?
Before taking any shot we should have in mind what is our goal with this image. If we shooting objects on white, we seek for extreme sharpness so fast shutter speed is the best option to avoid even the smallest movement. Objects on white are special category and shutter speed is not so critical because we can get rid of movements on several ways which I covered in my other article. But if we have descent amount of lighting then the best option is fast shutter speed. The other use of fast shutter speed is to "freeze" something that is obviously moving fast. See the water splash image included. "Freezed" movements are always exciting because image shows details which human eye cannot see clearly. In nature some things are too fast and lazy eye cannot catch all the details.
Now, as every principle has two ways, you may want to have blurry or unsharp image on purpose. There are situations where movement adds to your message on image, depicting some action or faking movement. Example of this is shooting rain drops in counter light. Very fast shooter speed will record dots while very slow will cause image to be covered with lines from top to the bottom. We should find the shutter speed that vill produce short lines caused by raindrops.
So, shutter speed has its creative value. Perfect lighting conditions will give us full range of controlling the capture. But as we know perfect conditions could be done only in properly set studio. In nature, we need to have clear idea what we want to achieve regarding action and movement, evaluate the lighting conditions and then decide about shutter speed at the first place. Simply sadd, when your image concept deals with movement/freezing shutter speed is a priority. If you are skilled you may try one second shutter with zooming your lens at the same time. You may get nice motion blur effect to your image. Sure, always think ahead if this will be stock photo or just art.
The best advice would be: first get known of your camera and its performance features, and then experiment with different setups until you figure out what is best in different circumstances.
Until next time, keep shooting!