Looking for/write a GM step by step guide

It's very hard to explain how to be a GM through writing.

Luckily technology has made the issue obsolete. You can learn by watching others play the game!

http://geekandsundry.com/shows/critical-role/
https://www.youtube.com/watch?v=j_fGKY44DaI&list=PLjZRIC6PMEFku-_jr2Pe4db4DCuyjVKSl

these are two examples for you!