Introduction
This is my first build ever, trying to build a strong build for the "UP" yorick.

Pros

Great Chaser
Somewhat tanky
Great 1v1

Cons

Not having any Hard CC
Easily CC'ed
Slow and squishy early game
Needs a bit of farm
Not a easy champ for new comers

Taking Arp reds and Arp Quint for the early dmg
Mp5 P/level yellow, this champ is really mana starved so be careful, don't spam it and you should be fine.
Blues is personal choice either CDR p/lvl or Flat Attack speed are nice

Really self explanatory CDR / mana masteries + ghost and flash masteries.

You also go 9/21/0 for more tankyness

Maxing out Q first since its his main dmg ability, and E next for the sweet lifesteal to be capable of 1v1, and go less times to base.

Tips.
Use your Q on a close minion to be able to catch up a running enemy, or to escape certain death.
Use E also when running that bit of more hp can save you *** from a skill shot.

Flash - Best summoner spell out there for many reasons (flash over wall, catch enemies, escape turret dives...)
ghost - Other great chase/run spell, can also be replaced by Ignite or cleanse

Boots + health pot is great for you to harass early game or escape enemy skill shots since yorick is a slowpoke champ.
Finish off Mercury's Treads to get some MR and the sweet CC GTFO :D

Now get your sheen, and you will see ur Q hitting like a truck.

"Having mana problems?? GET A MANAMUNE!" NO! really dont do it , manamune on yorick just plain sucks, get a Philosopher's Stone, MP5+HP regen+Gold, best item EVAR!

Finish your TF and just go for the kills, ur Q speeds you up after you hit an enemy + TF slows the enemy + ur W slows even more + E to heal ur self, have fun melting faces :)

Since 1v1 isn't no fun get a spirit visage, and your E+Spirit visage will give you 65% healing. PS. dont try to 1v5 ur not super man.

MANZ we have some seriouz dmg, soo get tanky sunfire cape + banshee and your unstoppable literally on fire.

To end the chaos get a Madred's Bloodrazor just for the sick of hit and be the hardest to kill carry ever.

Try it out comment and rate.

Good luck summoner :)