Shutter lag refers to the time it takes from when you press the shutter button, to the time the camera actually completes the shot. This can be a problem sometimes for digital cameras and in particular, digital (point-and-shoot) compacts and can certainly be a problem in many photographic situations; especially if your subject is constantly moving about. Or, when you are waiting for that decisive moment.
The best way around this is when you take the shot just press the shutter button halfway and hold it for a second or two. This allows the camera to perform all of the functions it needs to before you press the button all the way. If your camera allows for manual focusing, set your focus at a distance that is comfortable for you. Say, 6 or 8 feet from your subject (about right for this sort of photography). This will then help speed up the process and allow you to get on with composing your shots.
Neglecting to do this can result in fuzzy out-of-focus photos.