A succinct summary prepared by the Natural Resources Defense Council of the lighting types available in stores and how much money they can save you. For more information view the Your Guide to More Efficient and Money-Saving Light Bulbs (PDF). Keep in mind that the estimated savings in the Guide are based upon average nationwide electricity costs of 11 cents per kilowatt-hour. In New England, costs are higher: 17 cents per kilowatt hour. That makes the difference in energy costs between a standard incandescent and more efficient options about 50% greater in our region than indicated in the NRDC's guide.
Lighting Made Easy is a one-page summary prepared by the Environmental Protection Agency (EPA) on the various types of energy efficient bulbs currently available for different fixtures, including recessed cans, pendant fixtures, outdoor floods, and more. This guide also provides a useful summary of what color light works best for what purpose.
A reference prepared by CMLP that answers some common questions, such as "Are CFL and LED bulbs dimmable?" and "CFLs don't seem to last as long as the manufacturers claim. Why not?" For additional information view the Guide to Energy Efficient Lighting (PDF).