I've just finished a certain master's degree but that left me a huge stack of printed notes along with the personal notes that I've jot down during the classes.
Therefore, the best way is to scan them all and to keep them in your computer, index them properly so that I might read them again when required.
The scanning process is quite tedious even I've a scanner with auto-feeder. The problem comes when I'm scanning double-sided notes but the feeder jammed in the middle of the process. Anyhow, it's still way better than scanning one by one.
After scanning, I would keep those pages with one side blank and to send the double-page sheets to the recycler...