I do know there are a couple of websites for cephalopod enthusiasts:
https://zapatopi.net/cephnews/ https://tonmo.com/
Textbooks:
Cephalopod Cognition by Anne-Sophie Darmaillacq (Editor), Ludovic Dickel (Editor), Jennifer Mather (Editor)
Cephalopod Behaviour 2nd Edition by Roger T. Hanlon (Author), John B. Messenger (Author)
Personal anecdotes:
The Soul of an Octopus: A Surprising Exploration into the Wonder of Consciousness Paperback by Sy Montgomery
I do know there are a couple of websites for cephalopod enthusiasts:
https://zapatopi.net/cephnews/ https://tonmo.com/