the best way i feel is to start out as a groundman.you learn so much watching a climber day in day out.and have him instuct you as he is doing it.then start out doing climbing in small trees,getting used to the feel of the saddle/ropes/knots/weight of a saw,etc.then just keep performing as you go.in time you will be in large trees comfortable doing the same.hands on and seeing it first hand alot is better than any book.but for sure read all the books you can also.as there are diff tools/ways of climbing that may be more to your likeing.