This is my guide for the one and only Olaf. He is a very strong laner, but this guide will be for people wanting to take him to the jungle. He can clear camps really fast thanks to his passive.

I'm not going to use fancy images or whatever, just straight to the point how i feel Olaf is at it's best.

I have chosen these runes because they are strong for a jungler, the attack speed helps him clear the jungle really fast, the armor and mr/lvl help him survive, and the armor pen is great for late game obliteration.

Other viable runes:
Armor pen marks
health quintessence
movement speed quintessence

These are pretty standard AD champion jungle masteries,
9/21 or 9/12/9 could also work but i prefer these.

Smite and ghost are standard spells for a jungle Olaf,
ALWAYS TAKE SMITE ON A JUNGLER.
ghost can be switched for exhaust or flash.

Pros:
-Fast jungle clear
-Very strong late game
-Very tanky
-Strong ganks if you land his q
-Has the best skin of all champions (brolaf)

Cons
-Falls of a little during mid game, depending on build
-Can be crippled
-Is mana dependend in the jungle, so he can be slow'n down by stealing his blue.