i have 16 various
watt cfls in a closet i generally grow about 4 plants at a time. i'm now in my third grow. the first two were extremely successful. use all the light you can get and follow ALL of the instructions you find on this site. ie: don't over water, don't over fert., don't violate the 12-12 rule and open your closet to show others(keep it as dark as possible for the entire period), use pots that have at least 1 gallon of dirt per foot of height (otherwise you risk root bound). i'm probably forgetting some directions, but spend some time on the instructions that are here. make notes and don't get cute and decide to do something different and try to grow a "super plant". following what others have done here for successful grows is the best advice. it will be worth it when you harvest.
your question about cfls is a good start, but do your homework and you will be elaated in about 3 months.