How do you become a certified fitness trainer?

Question

What would the program entail and how long does it usually take to complete?

Answer 1

It depends on who you get certified by, what your current level of education and background is, etc.

Here are some sites where you can read more on the various programs:
http://www.afpafitness.com/
http://www.nfpt.com/
http://www.afaa.com/
http://www.nsca-cc.org/

Answer 2

I'm looking into the NASM (National Academy of Sports Medicine) program... they offer a training/educational course and once you purchase it, you have 4 months to complete the exam... it's home study and their premium package offers a live 2-day training program. Check it out.