The phrase “everything I learned about x I learned from n” is probably kitsch and hackneyed, but in the case of bicycle maintenance, Sheldon Brown and his website, it’s absolutely the case for me.
Sheldon's is a classic especially on older bikes or specialist parts like hub gears. Is it still maintained since Sheldon died?
Yes, there is someone (a meat space friend, I believe) who keeps the site up and running and even adds new content from time to time.
I wonder how bike maintenance will change with ebikes and electric shifting