Part of the problem with a codex of stuff specifically targeted towards new GM's, is nearly every article written has at least something a new GM can use/learn from to make their game better. (Unless you're counting the "beginner guide to GMing style articles which I don't think we have any of here)
The best thing I can think of for advice when it comes to new GM's is get out their and run games. Doesn't matter the setting or rules, just go game!
Much like martial arts, creative writing, and painting, reading how-to books will be a good way to get a rough feel for the hobby, but until you actually "do it" you'll never really reach any level of proficiency or being to hone your talent for it.
Doesn't matter if the game is a smashing success or abject failure, until you run a few you'll never know just how much fun it can be and what areas you need to work on. (Also most players will cut a new GM lots of slack and do their best to help them where possible.)
