I like the "tree format" programs for organizing information and making lists, but most are too slow to use for note taking.
I saw one on freewareppc.com called "ADB Idea Library" that you might try.
http://www.freewareppc.com/database/...braryarm.shtml
I experimented with these programs initially. All of them were easy to use: Listtree, Notetree, Easylist (Ultimately I chose Trenotes for other features.)