Hearthpwn

The combo is to play Auctioneer, Flamewaker, and Apprentice together for almost infinite damage (the rope limits the damage).

In mulligan, look for Arcane Intellect and Frostbolt. If you suspect your opponent to have an aggressive deck, Flamewaker is also good.

During the game, your focus is to stay alive with removals and freeze spells, but also to discover your combo pieces and Emperor with Arcane Intellect.

The goal is to play Emperor on Turn 6, or on Turn 5 if you have the coin. This guy enables the combo. 

Ideally, you want to have 2 Emperors so that you can play another Emperor on Turn 7, allowing you to play the combo earlier in the game.

When you're going off with the Auctioneer, keep in mind of the time, and discover relevant cards (another flamewaker if you're floating 3 mana for a faster kill, freeze spells to stop minions, burst spells if you think you can kill your opponent fast enough, back-up combo pieces in case your board gets wiped).