I've got with Yorick 35 kills, 6 deaths and 31 assists in 4 Ranked games.
I won all of them on the top lane, so i got 4 wins and 0 loses in season 3.
Just farm on laning phase and roam sometimes with teleport.
If you got your tear of the godness, you have to poke/harass the enemy top laner.
Stack your tear and farm and it's GG!
Try to freeze the lane, so the enemy have to come closer and then it's easy to harass him/her but don't let him/her come too close.
Against Pantheon or Garen for example it's important to prohibit their passive with auto-attacks or your abilities!

You need only your E spell and Auto-Attacks and sometimes if the enemy top laner wants to farm use your W spell to harass him/her.
At the enemy turret don't use your spells because the ghosts are attacking the enemy champion so the turret will attack you if you are standing to close to them.

Pros:
-Yorick has a strong early game
-He uses CC abilities
-Yorick has health recovering abilities

Cons:
-Needs a lot of mana
-Easy dodge his W ability with tenacity
-Good enemy player are using crowd control against you, if a team fight starts