I found that hiring a pro (on the side) and letting him know up front that I wanted to learn was the best way for me. I too did all the research, have about 1k tied up in videos from Arbormasters (excellent by the way) and books and another 1k in equipment (by the way it ain't cheap to get setup!), but nothing like first hand instruction and I got the tree removed to boot. One thing I observed early on, this is not a trial and error line of work!
I knew the ground work and Arborculture from over 20 years as a Facility and Grounds Manager (my current assignment owns and maintains an Arboretum), just wanted to get off the ground!
If you are in SC, there are serveral good schools/camps in GA. Some have one day weekend try it climbs.
Still the best is to expose your self to experience how ever you can.
By the way, I am going to attempt the certification test(ISA) this coming March!
next goal... 18 months of climbing then Climber Certification.
Rick H...