Bob Doto’s, A System for writing is a good entry into the world of note-taking books. He is concise and direct while still hitting all the high points I think need to be hit to create a good practice of taking notes and producing writing/content from them.
We both agree that a key point is not merely taking notes, but going back and working your notes. That if you don’t do this crucial step of spelunking through your notes then you’re missing much of the benefit of a healthy not practice.
If you haven’t started reading about taking notes, this is a good book. If you’ve read a bunch of books, this won’t be revolutionary, but it’s not a waste of your time.