This is the ultimate guide for several reasons. Exhaust = intimidating. Ghost > Flash Because your W is a flash - except longer and much less cooldown. Treat it as an escape route mostly.
These items give you endless Mana, along with mass Mana Regen as well as synchronizing with each other, giving 40% CDR, massive attack speed, alot of AD DMG, and alot of AP DMG.
Beserkers and Vamp allows survive-ability, the Sheen gives great poking with the B.F Sword fortifying this. the chalice gives MR (which corki needs) along with Mana Regen which is essential to a corki early game. Really helps stay in the lane a bit longer.
The rest is needless to say - your just taking those 4 initial items and building them into their late game evolutions. Build tooth later, and G.A to beef you up, as well as giving you one last shot to get that penta kill =). Hope you like it, and enjoy.