Save Energy and Money with More Efficient Lighting
The average household dedicates about 5% of its energy budget to lighting every year, with much of the cost owing to the few lights that are on the most. Switching those frequently used bulbs to light-emitting diodes (LEDs) is a great place to start. Find the 10 lights you use most, and the lights you use at least one hour per day, and make the change.
American Council for an Energy-Efficient Economy: More information about types of lighting and choosing a bulb and fixture to suit your needs
US Department of Energy: Lighting choices