Well...that's a loaded question

Yes I think you either have it or you don't. You have to love it, unfortuantely you have to love even the tough parts if you're going to be good at it.
It's not all sunshine and roses and playing with puppies. You will be bitten *and if you never in your career challenge a dog to where he tries...you're probably not doing it right, there's always that one dog that simply does not want to let YOU or anyone tell it what to do*
You can't be afraid of the bad ones.
You can't kill the really crappy owners, no matter how much you want to.
As a rule, most people don't have a CLUE and it's your job to make them think "dog"
You will need to set aside some of your AP rules if you think of dogs that way.
You will need to give really lousy advice sometimes--if someone comes to you and asks for risk assessment on their dog and that dog then attacks the neighbors kid after said it was totally workable, you will be called into the law suit and you will need to prove that either you advised them to put the dog down or that they didn't follow instruction or chose to blatently ignore you.
There will be times where in spite of an owners love and your dedication a dog can't be fixed.
There will be times when despite our dedication and the dog's potential an owner will ruin a good dog.
There will be times when in spite of all your experience you won't be able to help someone.
You will see the bad side of dogs and the worse side of dog ownership.
Now, if you're still with me.
You will help people to have an understanding of their dog.
You will have the power to turn what was a bad match into a lifetime friendship.
You will have the power to make a huge impact on animals and their people.
Once you've paid your dues and have lots of experience under your belt you have the potential for a very good income, especially if you specialize.
Even though I specialize in scent work, my most satisfying moments are when I'm driving through town and see a formerly obnoxious dog walking along beside his owner on a loose lead.
In spite of how long I've been working dogs in scent work (narcotics, search work, highest levels of tracking) I still often stand with my jaw dropped watching a dog and knowing that while I'm a good trainer...in scent work, only the dog truly knows if he's right.
Now, onto "HOW"
Experience is the best teacher, first things first, contact the school you went through with Blaze, ask them if you can volunteer for them. Tell them you're thinking abou training professinally and you want to get a feel for whether it would be a good fit for you. You can also ask friends, neighbors, whatever if you can take their dogs through classes for them--it's not perfect for the dog--but it's way better than no training and gives you the experience. I strongly recomend taking these other dogs through a class--even professional trainers train their own dogs with another professional--that's the purpose of this--often you can't see little mistakes you may be making and we ALL make them, so having another eye to watch what you're doing is always helpfull--especially when you're in the beginning stages.
Once you do that step, you can then decide if you want to keep on there as an apprentice of sorts until you know enough that you can start training some dogs on your own. This is the time to go into the local shelters and offer to train some shelter dogs--you don't have to be the best to make a HUGE difference in the adoption perspectives of these animals, you can be the difference between going home with a family and being killed.
From there you can go onto some of the schools that offer courses on being a dog trainer. Personally I think you're better just paying your dues as a volunteer if you *can* but not everyone canmake it that way.
Ultimately, you're looking at at least 3-4 yrs before you can start making any money at it, but you can certainly be making a difference earlier than that.
Books
Monks of New Skete, how to be your dog's best friend.
Wendy Volhard, Drives
Keohler's obedience books
Schutzhund Obedience-training in Drive by Dildae and Booth
An Owners Guide to Dog behavior by Ian Dunbar
Child Proofing your Dog by Brian Kilcommons
How to Speak Dog by Stanley Coren
Mother Knows Best by Carol Lea Benjamin
That should get you started anyway!