The EPA’s Energy Star site has lots of information on how to select and make the best use of compact fluorescent light bulbs (CFLs). 
CFLs are available in a wide variety of shades of white light, ranging from yellowish to white to bluish white light, which allows you to customize the mood of your space. Many CFLs come in “warm” colors to match the yellowish light of incandescent bulbs, but you can also choose “cooler” colors with whiter or bluer light.
Read the entire buying guide.
