The secret to good macro photography is lighting. You can buy special macro photography kits, with diffuse daylight-balanced lights on adjustable stands, and they are very good, but you can get results very nearly as good using simple household lights. It's best to use at least two for bright, even illumination and minimum glare or shadow. Here I've simple used two normal reading lamps.
The bulbs are of the energy-efficient fluorescent type, and supposedly equivalent to 100W tungsten bulbs, although in fact I'd say they're more like about 80W. The important thing is that both lamps are equally bright, and are about the same distance on either side of the camera. Make sure you position them in such a way that the tripod isn't casting shadows over the area you want to photograph.
The angle of the lights should ideally be approximately 30 degrees from the horizontal. This is especially important if the object you are photographing is reflective, such as a piece of jewellery or a glass-framed picture. A higher angle could result in glare being reflected into the camera.
The fact that the lamps are not daylight-balanced (i.e. the same colour as natural daylight) doesn't matter, because nearly all digital cameras have a manual white balance feature that will compensate for this. You'll usually find it in your camera's menu or via a function button, in the list of white balance settings. The icon for it is a square with two wedges under it. Normally you'll have to press a button, often the shutter button, to set the white balance. Check your camera manual if you're not sure how to use this feature. Switch your lights on and set the white balance from the white card or paper you've placed under the camera.