Hello, I am bennygump and I will be taking you through how I play Yorick in different situations and why.

The work of gravediggers is essential amongst the living, but invaluable in the Shadow Isles. There are many shades of death there, and each is embraced rather than feared or reviled. One can only ascend from one state to the next with the magical aid of a skilled professional. At the end of the first Rune War, Yorick Mori made his living as a gravedigger. His family owned and maintained the Final Rest Memorial, one of the oldest cemeteries in Valoran. The shovel he employed for his work had been passed down for generations. Each gravedigger taught his son that this shovel was imbued with the spirit of every forefather, and that those spirits would protect him during the long lonely nights amongst the tombstones. To his eternal regret, Yorick died without an heir, bringing the proud Mori line to a close. His body was interred with his shovel in the family mausoleum, and the Final Rest Memorial soon fell to ruin. Death, however, was not the end Yorick had expected.
Yorick emerged on the haunted shores of the Shadow Isles – not quite dead, definitely not alive – still clutching his beloved shovel. He soon learned that with it he could act as a ferryman for the Isles' undead denizens, helping them climb death's many-tiered ladder. This proved a curse, as a gravedigger must "bury his quota" before he too can ascend, or so the legend goes. No one knows what "his quota" is. Yorick dug tirelessly, waiting in vain for the day when he would be freed of his burden. As decades turned to centuries, the shame of his failures came to a head. He returned to Valoran to find his corpse, convinced that salvation might be buried with it. When he arrived, no trace remained of either the mausoleum or the memorial. Hope nearly lost, he discovered the League of Legends, and there saw an opportunity to immortalize the family name he allowed to be forgotten ages ago.

"Die first, then we’ll talk."
―Yorick

PROS

Has minions to do his biding.
Can turn the tide of a team fight with his ultimate and minions.
Strong early game.
Almost impossible to lose top lane as Yorick.

CONS

Mana hungry early game.
Falls off late game.
Somewhat squishy.

Like all champions he has strengths and weaknesses.

For all my Yorick builds I start off with manamune because it gives him great mana regen and attack damage early game. For my AD build you are trying to utilize omen of famine and do massive amounts of damage (around 300 damage) and gives you amazing life steal with your bloodthirster. Also your omen of war is like a built in sheen and with an AD build it is extremely strong in 1v1 fights.
In my AP build I get all my items to try and utilize omen of pestilence the most. Which allows for you to be able to slow enemies trying to get away from you or enemies that you are trying to gank.
In my Offtank build I build mostly for Armor but you can change it around if the team you are facing has a lot of AP champions, in this build I also have a higher priory on damage so that omen of famine to help you survive while getting focused in team fights.
Note, in most team fights you want to ultimate your ADC to get more damage out of the minions, or you can ultimate a teammate that is about to die to get him back into the fight for a short amount of time, think about your choices and pick which is best in that situation.

Farming should be pretty easy even if you are solo top. Just summon minions onto champions to back them off or summon minions on enemy minions that are about to die and get some free gold. Note, I usually use my omen of pestilence and omen of war on minions while keeping my omen of famine for the champions.

Yorick is one of the best solo top lane champions, he does not need ganks often but if he gets one he usually gets at least a kill because of his slows and massive amount of damage that he does with his minions. I hope this build helps you like it helps me in game, comment and tell me what you think I should change about this build and I will change it if I think it makes sense.
Cheers,
Bennygump