To add notes, set properties on them, and label them as a Category or Message.
The treeview organizes categories and messages. For each node you can add notes via a rich textbox.
The treeview supports dragging and dropping messages to different categories.
The toolstrip menu contains similar funcationality as a word processor where you can change font, text size etc. The save button serializes the labels and notes to a binary file in order to be retrieved on a later load of the form.