I've no problem with using LibreOffice for most of my document needs, but i haven't found a good substitute for microsoft's OneNote yet. I mainly use it to plan my RPG games and it helps a lot. What alternatives are there for organizing notes on linux, with similar features to those that OneNote provides?
+1 for Cherrytree, I can even recommend it on Linux. The tree structure makes it so much better to sort things than OneNote with the limited depth.