I am a slow learner, new to photography, and use a Nikon Coolpix P610. Many of my pictures of moving subjects (rodeo animals) are blurry. When I try to adjust the shutter speed (supposedly increasing the shutter speed), my pictures appear dark. Will someone please explain, in a step-by-step detailed and simple way, how I can take sharper pictures of fast-moving animals? Sometimes I feel so lost. 