Some of it's over my head, but I found most of this "carbon arrow University" pretty helpful. I'm still learning, but this kind of thing really helps for me. Maybe it'll help some of you too????
http://www.huntersfriend.com/carbon_arrows/hunting_arrows_selection_guide_chapter_1.htm
http://www.huntersfriend.com/carbon_arrows/hunting_arrows_selection_guide_chapter_1.htm