A link to Papel's homepage:
http://papel.teiru.net/papel/index.html
The site will give you lots of info; if you're not a visual person, it may not be the program for you. You begin with a bare screen, save it as the name of your project (New Story), then right click anywhere on the screen. A 'Papel' will open, this will begin as a box in which you choose the papel type - character, location, plot, scene, etc - and name it. You can add some details in this box. This is the property box. Close it, an icon appears on the screen which is relevant to the type of papel. (I spent lots of time customising my own using the theme options downloadable at the site.) If you click on the Papel, a txt box opens into which you can type more ideas about this character, or whatever.
While I was doing Nano, I found this a great way to keep track of ideas which would pop into my head; if I wasn't at my computer, I'd make a note, get to the pc and open Papel, copying the note to the relevant part, or creating a new papel (icon).
I like this way of keeping ideas together because it allows an overview of the entire novel. I then outline in Word etc.
Papel is completely free.