As Yorick top I like to get manamune as my first full item after boots because it allows me to continuely harass the person I am laning against while gaining mana and attack damage in the process. I next grab sheen because sheen is very useful when combined with Yoricks q it is a devastating combo. Then the spirit visage make yoricks e restore even more health. Then you buy Triforce which then makes ur q as Yorick very very powerful. It also make u very tanky and gives you more mana to go along with manamune. Then you get atmogs and frozen mallet to finish the offtnak build with health and damage per amount of your health from atmogs.