This is my first guide so I'll give it the best I've got. I build Yorick as a tanky dps that can last long in team fights and put out good damage also.

I use armor penetration marks and quintesences to help with my damage dealing, with armor seals and magic resist glyphs to be able to take some more damage.

I use a basic offense build and go into defense for the armor, magic resist, and dodge for durability.

I build my items to give me plenty of health for durability and to do good damage. Getting a warmog's armor and frozen mallet with atma's impaler to get plenty of health for the attack damage on atma's impaler. and a youmoos ghostblade to get the cd reduction and attack damage. And a trinity force to help omen of war do more damage and get a little extra health.

I just use a basic exhast/ghost combo to help chase or runaway. and get an easy first blood.

With this build Yorick can last a long time in a team fight and even if you get low on health you can ult and stay in the fight even longer. You can have a steady damage output and stay alive for a while so you can help your team get kills. Hope my guide helps, if you guys like it I may make another one for a different champion I like. Happy Summoning.