I have recently become absorbed by a series of videos on YouTube called Mastering the Lightning Network Reading Group
Each video contains a detailed discussion of each chapter of Andreas Antonopoulos' brilliant book. I find it easier to understand the difficult concepts by listening to others discuss and explain them than by trying to fight my way through the book on my own.
I've personally read these books and can highly recommend them: "Keys to Bitcoin" by Raphael Meyer, "Programming Bitcoin" by Jimmy Song, and "Mastering the Lightning Network" by Andreas Antonopoulos. They're all incredibly insightful and worth your time!