Where would i get info on becoming a fitness trainer?

i am going to school to a nutritionist and i want to be a fitness/personal trainer too. i would like to take courses online, and i can't seem to find any good sites that arn't just advertisement. anyone have any good suggestions on a good website that maybe help me?Where would i get info on becoming a fitness trainer?i'm not sure about online trainging, but if you go to careercruising.com, they tell you all about it, and courses you should have to become one.