Reply to u/EnvronmentalAngle at https://reddit.com/r/NoteTaking/comments/1o4zfjk/i_never_learned_how_to_take_notes_on_books_does/

I never learned how to take notes on books. Does anyone know of any good guides? Most I find are geared towards college students.

Given the things you're reading and what your ultimate goals on remembering and thinking may be, I'll make a few recommendations I think will be highly useful:

Start with Adler's short article on How to Mark a Book: - Adler, Mortimer J. 1940. “How to Mark a Book.” Saturday Review of Literature 6: 250–52. https://www.unz.com/print/SaturdayRev-1940jul06-00011/ (January 11, 2023). (Alternate .pdf copy: https://docdrop.org/download_annotation_doc/Adler---1940---How-to-Mark-a-Book-fehef.pdf)

Then move on to his more thorough work with Van Doren about how to read. It's relatively short and easy to read, particularly the beginning which might seem almost too easy and straightforward. Don't be lulled into a false sense of security though, as the final sections have some incredibly interesting and subtle ideas that many people, including the college educated broadly ignore. - Adler, Mortimer J., and Charles Van Doren. 2011. How to Read a Book: The Classical Guide to Intelligent Reading. Revised and Updated edition. Touchstone.

While you're reading it, you might appreciate a television version they made to support their ideas in the mid-1970s. In it they talk about some of the very books you're trying to tackle and how you might get more out of them. (The titles on the YouTube page are in Portuguese, but the show itself is in the original English.) - How to Read a Book. 1975. Los Angeles: KCET Los Angeles. https://www.youtube.com/playlist?list=PLPajsb520dyzNw9mHsZnrzi5w9N_amS7E (September 30, 2023).

While you're doing this, perhaps take a brief glimpse at how Adler (and many of his friends and colleagues) were taking notes on index cards to tear apart great books to better understand what was in them. https://forum.zettelkasten.de/discussion/2623/mortimer-j-adlers-syntopicon-a-topically-arranged-collaborative-slipbox

Whether you take your notes in your books (as Adler did) or write them on index cards or in a notebook or commonplace book as others have, you'll be well on your way to both better understanding and longer term remembering.

Good luck in your reading!'

edit: replaced dead link to .pdf