Create a white, well-lit space to take the photographs. A wall near or opposite a large window works well. Hang a white sheet on the wall. Cut a slit in it for an opening to the wall and hammer in a nail on which to hang a canvas. If photographing drawings on paper, skip this step and simply tape the paper to the fabric using clear masking tape.
Hang or tape the artwork to the wall. Use a level to ensure the work is exactly level.
Bring in lights to brighten the room. You can use standard lamps but use a white light or full-spectrum bulbs. Yellow light will alter the artwork colors in the photograph. If the painting is glossy and reflects light, angle the lights so they don't shine directly on the canvas.
Set up a minimum of a 7-megapixel digital camera on a tripod directly in front of the work. The camera should be exactly level with the painting to reduce parallax in the photograph. The higher the number of megapixels in a camera, the more detailed your photo. Higher megapixel cameras produce photos that can be blown up to very large sizes without losing resolution.
Center the photo in your camera's view screen with plenty of white space for cropping later on. Take several shots of the work at different zoom levels and lighting conditions. Never use flash on these, as it will leave a reflection on glossier paintings and drawings.
Upload your photos to the computer and pick out the best images of each work to develop into prints. Use a good quality photo editing software to alter the color balance, size and cropping of the image. Save your images in a TIFF file format, since JPEG files compress images and lose some detail.