About the certifications, I have ISSA, NASM, and Baylor Sports and Medicine, I also have the one from 24hour fitness
If you want to learn about the kinesiology aspect of training ISSA ans NASM are good
If you want to learn about Nutrition 24hour fitness is great
If you want to learn how to make money and keep clients and be a good trainer in general BAYLOR is the best. They will teach you everything from how to lift, and treat people so you can make your money. The hing with Baylor they only travel the country every other, so you have to be lucky to catch that cert.
As far as how much money we make. I am 21, and a full time student, and this past year I grossed a little more than 30,000 dollars. I didn't bust my ass the way I would if I was not in school. School prohibits me to train at peak hours of availabiblity, so I have to sacrifice some good clients.
But, thats the scoop on Personal training