The deck I'm currently using on the ranked ladder.
The idea behind it is straightforward:
Using Circle of Healing and your Darkscale Healers, you can gain both great draw (when used in conjunction with your Northshire Clerics) and super attack-heavy Lightwardens. It's good to hold onto your Circle of Healing cards until you have an opportunity to use them to one of these two effects. Since Lightwardens are rather flimsy, it's best to avoid buffing them unless you're about to attack or they're protected by a taunt minion. Once you a have a large enough hand, it becomes a viable option to spend your resources buffing a single minion with Divine Spirit (preferably X2) and Inner Fire. This is your end game.
In general, avoid using your Inner Fire/Divine Spirit combo unless it can immediately end the game--and as before, do not buff until you're about to attack.
That's about it! Enjoy smashing in faces!
Edit (April 25th): Removed X2 Shieldbearer and X2 Arcanosmith and replaced them with X2 Potion of Madness, X1 Shadow Word: Pain, and X1 Shadow Word: Death.
Shieldbearer, in theory, would provide you with some stall time when you buff him with cards like Power Word: Shield and Kabal Talonpriest, allowing you the time to populate your side of the board with minions like Northshire Clerics and Lightwardens. However, more often than not, Shieldbearer would just pose a minor annoyance for the first few turns. Potion of Madness is a much superior way of actively dealing with early game threats.
The reasoning behind getting rid of X2 Arcanosmith is much the same. Occasionally, you might wind up with a situation where for five mana, you could have a 3/2 and a 5/5 (using Inner Fire), but this is fairly situational and usually not an ideal way to use Inner Fire. Instead, another Shadow Word: Pain and Death should give you more ways to eliminate threats and maintain board control while you buff your minions.