Hello Jason
There is a group called the Kansas City Climbers (These are Recreational Climbers thou) but they can teach you the basic climbing techniques and you need to work with a Certified Arborist to get the other very important techniques used in Arboriculture and Forestry to become a good Tree Industry worker. The treebuzz.com is a good source of information for Tree Workers training and information on gear and equipment uses. Lots of discussions for preofessional Arborists that are willing to share and take you under their wing. Good Luck.
Edit: Buy the Video from Peter Jenkins on Basic Tree Climbing Techniques and order the Tree Climbers Companion book. Both of those are great tools to any new climber either Professional or Recreational.