I currently work at Petsmart both as a trainer and a bather. Since I'm not a groomer I didn't have to go to what they call "academy" training which is the 4 week program where you learn to cut dog hair.
The training to be a trainer program is 2 weeks with an area trainer though. I went through this 2 years ago and I have to say that I love my job. Yes, most of the people who come through classes at Petsmart are not ones looking to do anything special with their dogs, they just want well socialized and mannered companions.
When I hear stories about awful trainers at Petsmarts whos demo dogs nip at their pants and drag them around that makes me sick! I would NEVER bring in a dog who isn't ready to show off his stuff. Zumi, my 3yo well trained shepherd mix, makes for an excellent demo dog. Usually at the end of the class everyone starts asking me how to make their dogs as good as she is

Gary on the other hand, I haven't even considered bringing him in yet lol. I am sure he wouldn't be a good example! Some day though...when he is older.
At my store when a new trainer is needed my manager doesn't hire just any random person off the street who thinks it would be fun to train dogs. She looks for someone who has been working with dogs for a long time and is comfortable with talking to groups of people as well. Yes it may mean that they have no training experience, but she generally looks for dog savvy people as far as being able to read a dog's body language pretty well. That is so important when you are an instructor.
Since joining this forum I have learned so many things and my perspective has really broadened. I feel now that I am 10x better of an instructor now that I know so many different tactics to go about handling things. That is why I ask questions all the time!
Maybe one day I can get out of the company and move up to somewhere more advanced.
Just on a side note about the Banfield at Petsmart , I would be wary to bring my dogs there. Their vets are the ones fresh out of vet school and two of my fellow coworker trainers have had horrific experiences using Banfields as their vet...just a warning. I know vets have to gain experience somehow. I use my banfield for shots only (yay for discounts!). I would however never go there if my dog were sick and needed a diagnosis.