The obvious place to start is to compare the success rates of the clinics nearest you. These are compiled yearly by the American Society for Reproductive Medicine and are usually expressed as a percentage of live births per egg retrieval. Those numbers, however, should be interpreted with caution.
Some clinics treat more young patients, who have a better chance of success.
Others will take all comers, including older women or couples with long histories of infertility problems. But there are other important questions. Furthermore, doctors, like any professionals who provide a service, have reputations. Though it's hard to quantify, word of mouth can be critical.