I don't even think SB is something that can be 'taught'
I used to be a fair shot blocker and while no-one ever spent one second teaching me to block shots you get a lot better with experience, reading the fakes, timing your jump, keeping the ball inbounds, not fouling etc. One thing that does matter that can be worked on is obviously your athletic ability. A higher and faster jumper will block more shots. Having long arms is something that can't.