Dan - Welcome to the party.
If I were in your situation, a person just starting out in this arborist career, I'd try to learn all I could about the profession. I'd try to hookup with a good local firm that will teach you the basics.
I would attend some basic night courses in arborist/landscaping at the local schools if any are available in the area. As you know when starting out you won't make much money (because you don't know much are not that productive yet), but the time spent learning the various basic techniques will be time well spent. This information you learn will be with you for a lifetime, long after the paycheck is spent. The quicker you learn, the more money you will be able to make.
If you already have the basics and experience and you decide to go into your own business, I think it would be good to take some basic continuing ed courses at the local high school in basic bookkeeping, business law, and employee relations. These courses will probably not be a much fun as tree climbing/felling, but are very necessary if you run a business.
Just remember, the important thing when taking these course is getting a good grade. What is most important is learning useful knowledge to help you do a better job.
Lastly, don't forget "safety". Red Cross first aid training classes would also me very helpful. I'm sure Arkansas has rules that professional arborists follow to keep them in one piece (probably learned over time the hard way).
Good luck! It should be a great adventure! Let us know how it works out for you.