As we all should know by now, Yorick is probably the dopest champion made yet. As he is able to perform both as a melee fighter and as a caster whose nukes spawn ghouls. On top of this his ult will clone an allied ad carry (tryndamere works great) for up to 10 seconds tops. This Champion is so powerful that after you have read this guide, and have tried him and owned with him a few dozen times, everyone else will follow you, and before you know it he will be either banned in every ranked game, nerfed, and both eventually. So let us enjoy the age of Yorick while we still can gentlemen. (and ladies, you should try Yorick too you know)

Marks: Armor Penetration x9 Reason: Because Yorick is a melee champ who is going to chopchopchop, especially early game so you want to have as much an advantage as possible.
Seals (PREFERENCE): Seals of Fortide x9 Reason: For that unfair early game hp advantage so that you can get up and melee the wave and the enemies.
Glyphs (PREFERENCE): Magic Resist x9 Reason: The best possible glyphs you can get, and they help a earlygame Yorick resist magic damage.
Quintessences: Armor Penetration x3 No reason needed

This 15/15/0 build is currently the best imo, as now Yorick has masteries to help his early game ad, cd, magic pen, health, armor, mr, health regen, and exhaust. Exhaust is needed on him to fully utilize the offense tree (unless you jungle, another story)

Start with the typical Mana Crystal and double health potion routine. Yorick definitely has mana problems early game, and especially with this build because he has no runes or masteries to support mana regen. But you should be just fine with a little bit of timing and patience to nuke enemy ranged champions and rush them to Q chop.

Yorick is a first item Sheen champion, and this makes sense. He needs mana and he does ad both as melee damage and as nukes.

The rest of the items are as shown above. I do want to note that spirit visage is not needed if you get fed early game, because you want to spend your gold on bf sword to get that ad game advantage asap. However, he is a spirit visage champion otherwise, the reason being that you want to level E last in order to fully utilize the opness of the Q speed buff, and the W speed debuff. Spirit Visage makes a low level E heal adequately.

Also note that bloodthirster is almost the KEY item for Yorick, as it will give a total of 100 AD at 40 farms after purchase (assuming you dont die, you all know this). I prefer to get black cleaver before infinity, which you all may find odd because if you're going to get infinity at all, you should probably get it first, but the thing is Yorick works so well with a team that it is best to get the armor debuff to aid the ghoul summons output damage aswell.

The best skill Yorick has to offer is Q. It is considerably op at early game currently, and it will be useful all throughout the game especially to turret dive an enemy champion fleeing the lane. Yorick will be fully utilized if you level Q first and W second so that you can increase your movespeed, and decrease theirs. You will constantly be spamming W and E and then running up to melee the enemy champion.

I prefer: Exhaust and Ignite Reason: To get more dps out of Yorick to guarantee he will deliver enough damage to be op, plus exhaust is needed on him

You may choose the second spell as you wish, I suppose you could get an escape spell like ghost or flash with 1 of your defense masteries, but I prefer to flee battles with Q. It is not full-proof, and you may wish to go with 15/14/1 masteries and exhaust/ghost

Yorick in a nutshell

At level 1 you get W and 2 health potions to have something to offer the team for early ganks if your team wishes to do so.

You will proceed to build and get sheen/boots/bf sword (or SV if you are doing bad) as mentioned above.
During the lane phase you want to just harrass with W, and E, and run up and Q the enemy whenever you get a chance. Q is op early, so start getting aggressive by level 4 when you have Q at level 2. This is when Yorick gets dangerous.

Once you get your ult, you want to look for opportunities to use that ult. Maybe you can gank or rush an enemy in the lane. Or maybe you can clone your tank lanemate and have the revenant tank the turret for you guys. Or maybe a team fight has broken out and you want to save it for your fed ashe who has a bf already, or even BETTER your fed tryndamere with infinity's edge.

That's all Yorick is, soon enough you will be saying OP OP OP BAN BAN BAN BANBANBANBANBANBNABNABNAN

-Using the W ghoul to stop a powerballing rammus as he is coming towards you. (Or a nidalee jav/any particle/etc.)
-Using the W ghoul to help chop a turret. (No enemy minions around)
-Using E, W and Q ghouls to keep the enemy minion wave occupied while your minion wave and you attack their turret
-Using the Q ghoul to increase movespeed to flee a battle, or catch a target.

-Spirit Visage removed entirely from build, though still a viable option for a tanky approach if you aren't carrying that particular game.
-Item purchase sequence altered and it is up to you to decide if boots come before or after sheen/bf sword.

* Chalice of harmony solves Yorick's mana problems entirely leaving you to spam carelessly as you please. Rush a BloodThirster asap so you can start putting out high melee damage and nuke damage.

* Trinity Force is gotten earlier even though it will delay higher nuke damage so that your melee damage is more effective including the slowing proc.

I can now say with confidence that this build will lead to a steady Yorick win rate, and more importantly, now we all will know how to play the champion the way he was meant to be played. You can alter the item purchase sequence as you please, for example, get sheen before chalice, or boots before sheen, depending on how the game is going and how you have been farming.