Well, I guess those things are pretty different for people. I certainly will have read the text by Saintheart back in the days. I read all of it. Game Masters Guild I lurked. Market Theory. How to GM. Common Mistakes GMs make. I lurked games by guys who were good at GMing, started watching for patterns by my favorite GMs. I just had a profound interest in GMing before doing it and I liked that I had some stuff to read. Gave me some confidence I was prepared well.