When the tree service fell into my lap, I didnt know how to climb either. I was a bucket baby. Quickly realizing that I needed to learn, I sought out the top guy who had kinda retired, he still did some side work for long term clients and family. Talked him into teaching me. He beat the **** out of me physically and mentally. But, he taught me well. The basic fundamental's that I still use today. He showed me the "ropes" and then sent me on my way. Ya gotta find a Jedi, not some young kid that has only been doing it a couple years but a master that has made a career out of it. He may be a aashole and scream at ya when ya f up, but like a good Marine D.I. they have a way of beating the knowledge into you.
The books are great, full of info and "tricks of the trade" But nothing replaces one on one training, a hardaas staring down at you from above.
The biggest fear I had was trusting my gear, he took care of that first thing, made me get up in a really big willow and then pushed me off a branch. I thought I was going to die, I swung out and around the tree, came flying back in and smacked the trunk. My wife was there and she, from that moment on, hated his guts. He looked down at me and said "u can swing a truck off that rope, you weigh a buck 25, quit thinking it is going to break if you put weight on it"
Now, many years later, my wife holds him in the same high regard that I do and is thankful that he was the aashole that he was.