I used to put my thousands of flash cards in ziplock gallon bags and wrote what class it was. They were the kind with the hole punch on the corner and were kept on the big metal rings separated by chapter. Then I put the notes in folders if I felt I absolutely MUST save them and stored them on my shelves. Then I woke up one day and realized my bookcase was cluttered with so much s*** that I was never going to use again, so I just threw it all away. Now I get my books very used and write my notes in the pages. That way if I want to look up something I can see my notes along with the book and don't feel guilty about it because I bought the book pretty messed up already. It ruins the resale value, but I keep them anyways or let my friends use them.
If you really honestly feel that you need to keep your notes, buy one of those large black spiral bound notebooks from the art store (watercolor portfolio, blank paper). Then copy them by hand into the notebook and keep that in the shelf after you have finished the class. Thats the easiest way to see if you're keeping the notes just to keep them, or if you sincerely feel like you will use them in the future.
Or you can be lazy and just tape them in there haha.
Or... Buy a thumb drive and take a picture of the notes and load them on there with a folder for each class.
Just throwing out ideas haha