I get approached with questions about certifications on a daily basis. In fact, I have written a few different pieces on the subject. You may find “The Certification Maze” helpful.
Also, The American Council on Exercise (ACE) has a handy online tool that allows you to compare and contrast the various personal trainer certifications that are available. It’s a really simple way to look at what kind of prerequisites you may need, what the exam entails including cost, information about study and preparation, and some of the professional benefits you may get. It’s a very nice resource for those who are considering becoming a personal trainer.
Other similar topic articles: “Membership Has Its Privileges“.