I am new to Yorick. In my opinion he is a fun champion to play, and I have been playing him since before this recent patch that buffed him. Basically this build focuses on durability as well as damage output. Just a small comment, the attack damage posted in his stats above doesn't include manamune's or atma's impaler's passives, which add about 100 or so ad.

Pros

tanky
funny to watch run
r spell does great damage, is just fun to use
can lane for a very long time after getting some mana regen

Cons

is best as an offtank carry, not too versatile on this
r spell only works to change or help a team fight about 50% of the time
squishy early game

Yorick is a complete AD champion. All of his abilities scale based on his AD. I use the armor pen marks and the AD marks because of this. The AD marks can be changed for armor pen marks if you so choose. Yorick can never have enough armor. Thus I use armor seals so as to make him less squishy early game. The quintessences are for the same reason as the marks, but can be changed out for basically anything pertaining to a melee AD champion. Finally, I use cdr/level and cdr glyphs because at max rank, his omen of pestilence has about a 12 second cd. Omen of pestilence helps him gank nicely, it slows and does initial damage + it does damage while ghoul is still hitting, so using it more often helps a lot. Also being able to heal using omen of famine will help you stay in the lane more.

I start off the game with a Doran's Shield for the health regeneration. Also early game Yorick tends to be very squishy, so this helps him lane longer by reducing damage taken and increasing how fast he gains health. Normally I don't go back to the shop until I can buy Tear of Goddess, but if your facing some ranged opponents and you have low health it would be best for you to go back and just buy a Meki Pendant. Your goal is to rush Manamune. Manamune works well with Yorick because he uses mana up fast early - mid game, and he uses his spells often. Every few spells your attack damage goes up 1-2...this stacks nicely with a full game. Next I grab Mercury Treads for the Tenacity they have. This will help you out a lot, because a stunned Yorick is usually a dead Yorick. Now personally I don't go back to the nexus again after I grab Mercury Treads until I have enough for Warmog's, but it might help if you go back and grab a Giant's Belt before hand. After this I grab some part of Atma's or the entire thing when ever I go back to heal. Atma's should be the last attack item you get. Manamune and Atma's should give you somewhere between 230-260 attack damage, this is MORE than enough. Depending on how many ap champions you are fighting the last two items of the build are situational. I like to grab Spirit Visage no matter what because it really synergizes well with Yorick's e spell, and it adds some health and magic resistance. Now Force of Nature is always an all around good item to get, but if you are being stunned or snared or silenced often then grab a Banshee's Veil. Yorick will die FAST if he can't attack. As stated in the title this is an off-tank Yorick build, so if you have any questions as to what to get for a full dps build, then feel free to leave a comment.

When I am laning I farm minions using the w spell. If I wish to harrass the enemy team I use the e spell, and when ganking I lead with w then run in and hit them with a q and a fast e, and then I use my w again to keep them slowed. In a team fight I start with the w spell, hit the tank with the e spell (unless it is 3v2 against you...then I use it on the squishiest of the enemies) and then I use q on the person I am killing.