Not gonna write a lot, but still a quick guide:

The goal of the deck is simple; try to draw Knuckles as fast as possible and buff him with all the single card buffs. After you played most of your buff spells, play Zul'jin, with Knuckles still in your hand, to do that all over again. Once you're ready, play Knuckles and target The Beast Within on it. It will attack one of your opponent's minions, and his face! So taunt doesn't work ^^. Bdw. Eater of Secrets and Maiev Shadowsong are just tech cards, you can replace them as you'd like.

Both Fire Fly and Arcane Fletcher work really good together in this deck. As the main purpose is to cycle through the deck as fast as possible to be able to buff Knuckles as fast as you can.