Getting the best display results from your camera is largely dependent on the amount of light that illuminates your environment. Ideal conditions for a web camera should include a natural source of light coming through a window, but, of course, if you're using your camera at night, the moon will not suffice. You will need a lamp to make sure that people on the other end aren't just staring into a shadow or, worse, total darkness. A white fluorescent globe will give you the best lighting conditions for use at night. It is best to check the driver settings on your camera, though, as you may find that your camera provides different default settings for different lighting environments. The Quickcam Express, for example, features a 'Low Light Boost' among its image enhancements. It pays to experiment with these settings to find optimum results.
Other things to consider are the resolution of your camera and the window size in your application. Obviously, the lower the resolution of your camera the smaller the picture window will be, and attempting to make it bigger will pixelate the image. Also bear in mind that you will be transmitting over the Internet (possibly a phone line) so the more detail you send or receive, the slower the frame rate will be. With web cameras, the trade-off is always between performance and quality.