I found yorick to do very well jungling although might take some getting used to is very effective. my first time jungling with yorick i did extremely well. My first game jungling i had no problems whatsoever, i ended up at 13-3-9. compared to my games not jungling i benefited the team and ended up doing much better. When you get madreds razor it seems like you jungle faster than any other champion by far. you can kill blue in under 5 seconds at level 4.

Yorick is Relatively Squishy, so i like the 21/6/3 which gives him the bonus armor/magic resist and lets him do a good ammount of damage.

Madreds of course helps jungle quickly, and the life steal on wriggles lantern really helps until he gets bloodthirster. manamune i feel is necesary for yorick, because he tends to go oom pretty quickly. Once i get to working on my Atma's i sell the wriggles so i can grab a warmogs afterwards.

of course yorick's E is important because of the lifesteal, and his Q afterwards helps him do alot more damage while jungling.

i start with the smaller mobs first, unless someone is willing to leash blue which helps alot to spam his E more often. once you are 4... or have madreds blue is not a problem whatsoever.

Pros:
not easily ganked because of his lifesteal and W slow
jungles really fast

Cons:
Takes some getting used to