Chris,
Check out www.treebuzz.com/forum. It's a forum that is geared towards the professional arborist/treeworker. Folks there will be able to give you good advice, and just doing some searches should turn up some enlightening reading material for you.
I would also recommend purchasing a small book called the Tree Climber's Companion. It is full of VERY helpful information about safely climbing trees. Here's link to where it can be purchased:
http://www.wesspur.com/Books/tree-climbing-books.html