Another major difference between normal and macro photography is the depth of field. This describes the amount of your image that will be in focus, radiating outwards from your main focal point. With a macro shot, it can drop to as little as 1cm, meaning that a large portion of your picture may be blurred.
You can compensate a little if your camera has an Aperture Priority mode. This is represented by the letter A and will allow you to select a larger aperture value. If you can't select this mode, don't despair. As long as you get the main element in focus, the blurry background will add to the impact of the photograph.
Your camera's manual will tell you its closest focal distance in macro mode, but you can find out the perfect distance using a process of trial and error. Learning your camera's limits will help you to take quick shots - you won't waste time trying to focus on a subject you know is too far away or too close to your lens.