I watched a few videos by this author last year, and he's very good. Great at explaining things without jargon, but also goes deep enough to show the "sharp edg

I watched a few videos by this author last year, and he's very good. Great at explaining things without jargon, but also goes deep enough to show the "sharp edges". He had an email course that combined video lectures with homework assignments, and I found it a good way for learning. The material in this website seems to have the same feel.