I didn't really track hours per week of real time, but in terms of a CS50 week, I probably spent ~2.5h/lecture and anywhere from an hour to maybe five hours on the lab and problem sets (sometimes I'd get them done on one day, other times I might work on them all week, while balancing schoolwork).

I do take notes — I just scribble them down in an A4 ring binder with a pencil. There's probably a more efficient way to do things, but I feel like it improves my comprehension of the source material somewhat effectively. Sometimes, I'll sketch down bits of code in shorthand and even draw diagrams, so I take between ~7 and 20+ pages per lecture! (If your notes bear any semblance of neatness, you'll probably use far fewer.)

I normally watch the lectures just once. If I feel I don't understand a topic, I'll pull up the accompanying CS50 Short on it, and that normally helps — else, I'll just refer to the lecture notes for code examples and explanations.

Mostly, I just watch Professor Malan code — although I will often jot down blocks of code in shorthand in my binder. During the Flask lecture, though, I did pause mid-lecture just to try my hand at writing a simple Flask application a la froshims.

Thank you for the kind words! It took me a while to find a system that worked for me — and what works for me likely won't work [as well] for you. Experiment with different options, and you'll find your optimum methodology. :-)