Plenty of professionals are out there teaching on youtube. I can fix my car, my plumbing, my electrical, I can frame an addition to my house, I can setup an irrigation system. Rebuild a chainsaw, build my own furniture, refinish my floor, fix my drywall, concrete flatwork. These are all things I've done in the past year. The proliferation of digital video, high quality cameras, microphones and editing software has made it easier than ever to learn from professionals. Books just aren't the same thing.