What can I say about shutter speed?.. A lot actually! I will try to keep this short and sweet however.
The shutter speed refers to how fast/slow the shutter on your lens opens and closes. A faster shutter speed is normally used in well lit places, fast action (like sports) and/or when using flash. A slower shutter speed is normally used in poorly lit areas especially when flash is not an option. Slow shutter speeds can also be used to create some awesome motion blur effects (more on that in a later post)
So why adjust your shutter speed? The longer the shutter remains open the more light is captured. Too much light and your picture can be over exposed. An over exposed shot can also have blow out (areas that are solid white and has no data recorded)
Not enough light, and it can be under exposed. An under exposed shot can have blacked out spots (similar to blow out, but black).
So as part of the big three DSLR shooting basics (1.Aperture, 2.Shutter Speed and 3.ISO) you want to get familiar with how your shutter speed impacts your shots while using your camera. When you use modes like Aperture priority, Scene mode or Auto, you don't have to worry about adjusting the shutter speed. If your using Shutter priority or Manual modes then you set the shutter speed on your own based on the situation or desired effect.