Tel is NOT a Go expert, but he has been playing Go for about 35 years on and off (mainly off). At best, he was once playing at about a 4-5 kyu level. These days - who know? If you don't find these notes helpful, you are probably a better player than he is. One thing he does claim to know about is the mistakes that new players make, because he is still making them from time to time.
If you have any useful comments or questions, or even complaints, you can send them to him by email to email@example.com. By the way, he took some of these graphics from the British Go Association's web page. They did a very nice job and claim that they don't mind at all. [Some of the images on other pages come from the fine work by Peter Strempel and Tweet at gGo .]