This seems to be directed at someone, but in any case....
Tank lighting is normally done from the top. There are a variety of lighting options, depending on the needs for your tank. If you do not have live plants, fluorescent strip lights are most convenient--they don't contribute lots of heat, come in a few different spectrums, and will be suitable for nice viewing light. If you have plants, the lighting needs will be dictated in part by the type of plants, but generally, power compacts, VHO fluorescent and metal hallide are the choices. These lights vary in output, cost and heat output, but generally provide much more light than NO fluorescent. Incandescent lights, once very popular, can cause problems with heat output, but if you run screw-in CF bulbs, they too will work well.
I have timers for all my lights. They stay on for an average of 8-10 hours, depending on the setup.