I start instructing at the FBO that I am training at when I pass my initial. I will start at $18 an hour, and the average around here (western Washington) is less than $10k a year.
If you do your training at an FBO, they will usualy hire you when they have the need for another instructor. If they aren't busy, they will often make you wait until another instructor goes to the airlines, and you get their spot.