Because the guys at leaguecraft are hosting that competition, I figured I'd write a guide for my best champion.
Critiques are welcome. I focus mostly on tanking with what the enemy gives me and how to be effective early-game as his late game consists of ulti in, cleaver people, and slap things.
For the record, my rune page is crit for red, armor for yellow, and I need to replace my blue runes. I have -10% time spent dead quints in both my slots at the moment. I can build a better rune page for Mundo only, I know, but it also helps me a lot with the other champions I like to play.