Hello fellow summoners, my summoner name is ripperthedipper, and I play on the Eu west servers.
This is my guide for yorick as a solo top and tanky dps.

Yorick is an awesome champion, if played right, and with the right mindset. If you see him as one of those other champions, you will certainly not play well with him. Yorick is unique.

Pros:

-Spam ALL the skills.
-Awesome ulti
-Has everything you want from a melee dps champ (a slow, a heal spell, extra damage spell)
-Them ghouls
-Decent farm mid and late game
-Good pusher
-Sustain
-Has two ranged skills -> very good harass

Conts

-Eats mana
-Doesn't have very good starting stats. Lacks hp and attack damage early game (as well as a big mana pool)
-Ult can often be used on the wrong teammates.

These are the runes I use for yorick, feel free to use your own rune set. Runes pretty much depend on the situation you're in, and which champion you're facing. When you're facing an ap champ top, it can be a good idea to go for flat magic resist instead of armor. It really depends on how you want to play. You can even chose to go for offensive runes, instead of the magic resist and armor.

Pretty much the same as runes. Choose for yourself, and take whatever you need/want.
I always make sure i get the armor penetration runes, because I don't take armor penetration in my runes, and take mana (regeneration) masteries in utility, because yorick has mana issues (will discuss later on).

Yoricks passive. Eurhm, I don't know what to say about this, other than it's awesome. It releases a ghoul for every skill you do (except your ulti), and those ghouls have 35% of yorick's attack damage and health. They also heal you, slow the enemy, give you bonus speed, bonus damage, less damage taken, etc. It makes it important for yorick to have his ghouls up as much as possible in teamfight, so he can tank as much a possible, and still deal loads of damage.

This is quite a good skill. Your next attack will get bonus physical damage. In addition to that it will release a ghoul. While this ghoul is active, you get bonus movement speed. This is really awesome for chasing and/or escaping. I max it second for extra damage mid game.

A perfect skill for slowing and harassing your enemy. Since it scales with magic damage, and already has a nice slow at 1, I max it last.

Probably yorick's most important skill. The damage is considerable, it scales with bonus physical damage, and has a REALLY nice heal, which is why I max it first. This is a very important skill early game, because it will give you sustain early game.

Yorick's ulti! This is one awesome ulti. It copies an allied champion, and when that champion dies, he revives, and has the change to take revenge on the enemy before he/she finally dies. I use this to take advantage over a situation, to secure that i can still finish the job when I die, etc...
This skill has numberous possibilities.

I always begin with merki's pendant. It's quite annoying because it doesnt really give any bonus damage, but it is so important to have that sustain. It is important that you are able to harass the enemy without having to recall all the time to refill your mana.

I always try to stay in the lane until I can buy Tear of the goddess and boots of speed, but really not longer (unless it is needed). It is important that the bonus given by tear of the goddess is activated as quickly as possible, so your mana pool gets increased as quickly as possible.

After that I go for manamune, which I always get. It is the most important item on yorick. WIth manamune yorick isnt viable. He needs to be able to spam his spells or he isnt effective.

After that i go for mercury treads. Usually that is. There are other viable options. Ninja tabi is a good option against a heavily AD team (for example xin jungle, tryndamere top and caitlyn bot). In any game with a balanced enemy team I would opt for mercury treads tho.

After my boots I go for trinity force. It is a very good item on yorick. It gives you offencive power, gives you extra mana, and some extra AP for your w, and even extra bonus damage for your Q. You can also opt for frozen mallet if your team needs a more tanky person.

After that, go for Atma's Impaler. It gives you tankyness with the armor, gives you some extra crit strike, and changes your HP into attack damage. It is an awesome item (some say even overpowered) and i used by literally any tanky dps champion. (or mostly at least).

I usually go for spirit visage for some cooldown reduction, extra hp, and extra healing for the E-spell. You can choose for urself were to put this item. Sometimes I buy it, sometimes I don't. It all depends on the game.

The Warmog's armor is pretty much the same as spirit visage. It is a damn good tank item, and scales very well with atma's impaler because of the bonus attack damage. Again, choose for urself were to put in the build.

NOTE: this is only an example of a guide. There are numberous of other viable items, and everything depends on your team composition what you should buy and what not. Except for the manamune, there isn't really an item that is required on Yorick.