Setting the correct shutter speed on your camera can go a long way to getting sharp images. As a general guide for hand holding your camera try and aim for a shutter speed that is equal to or shorter than 1/focal length of your lens. For instance if you have a 100mm lens then a good shutter speed would be 1/100 sec. Below is an example of camera shake at a slow shutter speed.
There are a lot of different ways to change your shutter speed without affecting your exposure, here are some to try:
For increasing your shutter speed (when you want to freeze motion).
High ISO eg. 3200.
Wide Aperture eg. F/2.8.
Bright lights eg. Sunlight or flash lights, you can also try a torch if it's really dark.
For decreasing shutter speed (when you want to capture motion).
Decrease ISO eg. 50.
Small aperture eg. F/22.
Neutral Density filter.
Polarizer filter- plus has the added bonus of being a polarizer.
Shade the subject with an umberella etc.
Cloudy sky as opposed to full sun.
Early morning or late afternoon when it's a little darker and the sun is not high in the sky.