Does shutter speed affect your pictures?

Yes, shutter speed can affect your pictures in many different ways. Your shutter controls the length of time during which light can strike the film or sensor, and altering that period of time will usually have a profound affect.

Without getting too technical, if you are hand holding your camera, your shutter speed should never be slower than the focal length of your lens. It's easier for me to speak in terms of 35 mm film cameras, so I'll use the example of a "normal" 50 mm lens. If hand holding the camera, the minimum shutter speed for a reasonably sharp picture is 1/60 second. But that's a minimum, and if you really blow up the resulting image, you will see some overall unsharpness because of camera shake. The higher you crank the shutter speed, the sharper at least the plane of sharpest focus will be because higher shutter speeds "freeze" more motion, including the motion you impart to the camera. Humans are like bowls of jelly, in constant motion. Your heartbeat alone is enough to move a camera and smear an image.

But sometimes a slower shutter is exactly what you want, even when photographing a moving target. There's a technique called "panning" where you deliberately slow your shutter and move your camera to track your subject. It takes some practice to develop the skill, but try this with your 4-year old on a tricycle and you can make her look like NASCAR.

You've probably seen one of those gorgeous "moving water" shots where a stream and waterfall are all smeared but everything else is sharp. That requires a very slow shutter, maybe several seconds, a tripod, and no wind to move the foliage.

Higher shutter speeds, on the other hand, are good for "freezing" fast action. The main thing is, shutter speed has a big effect one way or the other, but don't forget that the aperture (f/stop) generally has to go in the other direction in order to hold the overall exposure where it needs to be. And we aren't discussing a phenomenon called depth-of-field at all because it wasn't part of the question. ----
Yes, shutter speed effects your photos and also greatly effects your photos depending on what you're shooting. For a base line of what they effects photos, is, the faster the shutter speed the darker the image will come out. The slower, the brighter, however it will have more chance of blurring depending on your lighting. When you use a fast shutter speed, you usually need separate lights besides the flash on your camera to brighten it up.

Shutter speed also is important when you're shooting a moving subject. Say, you like taking pictures of water drops. You need a fast shutter speed, say 1/4000 second with water. This will produce a very dark image, so you need some lamps in your setup and/or a external flash on your camera. The flash on your camera is not as strong as an external one or your lamps.

A slow shutter speed should be used when the lighting is good, so the image won't blur, and when shooting still life or non-moving subjects. For instance, flowers or even sea shells. You can use a 10/100 rather than a 1/4000 shutter speed as you don't need to capture a moving object crisply. A tripod is also very useful when using a slow shutter speed.

Another instance where slow shutter speeds effect images is in the popular pictures of 'meteor shows'. This gives the image that the stars are streaking effect while everything else is still. This is a tripod moment. :)