Hearthpwn

This deck tries to abuse the good old Divine Spirit + Inner Fire combos to burst Noth down at the right moment.

Key cards that i find essential for this deck and matchup:
* Silence: Noth uses a lot of Deathrattle minions, silencing that Unstable Ghoul or Abomination so it's deathrattle AoE doesn't clear your board and summon 5/5 skeletons for Noth can be essential
* Inner Fire: Essential to combo with Lightwell.
* Power Word Shield: Essential for Lightwell and Lightspawn + a resourse for card draw.
* Divine Spirit: Essential for Lightwell and Lightspawn combos.
* Mind Blast: This might be optional for some people, but using both Divine Spirits on your Lightwells/Lightspawns puts their health and attack at 20. After 2 swings, Noth will still have 5 hp left and he will be close to his 6 mana for Plague board clear + mass 5/5 summoning. Mind Blast can finish the game instantly next turn. Running 2 increases your chance of drawing it.
* Shadow Word: Pain: Nice to get rid of Undertakers and Flesheating Ghouls before they get out of control.
* Lightwell: Probably the most essential card in this deck. It heals you through the damage in the beginning of the match since Noth always ignores it. Combine with Divine Spirits and Inner Fires for massive burst.
* Shadow Word: Death: At some point in the game, Noth will most likely get one of his 5/5 skeletons out. Having a way to deal with it is a must.
* Mass Dispel: Another pretty great card to bypass Noth's Deathrattle minions and card draw.
* Lightspawn: Same as Lightwell. This is where your damage will come from.
* Holy Fire: Can serve as a finisher like Mindblast or a way to clear out Abominations.

Along with these cards, I chose for some other removal like Holy Smites and Holy Novas.

The Lightwarden can get some value, but its biggest setback is his 2 health, meaning he dies to the Abomination deathrattle.

Northshire Cleric is actually a pretty dead card for this matchup imo, it's just there to fill the spots.

!!! IMPORTANT !!!: I think Noth was programmed to only cast his Plague if you have 2 or more minions on the field. I base this on the fact that i once Mind Visioned his Plague on turn 1, yet he did not use it to clear my 20/20 Lightwell later on the fight on Turn 6.

Mulligans:

Your number one priority is Lightwell, toss everything if you don't have it.
If you have one, you can decide to either keep a bit of early removal or keep your Divine Spirits and Inner Fires in your hand.

Strategy:

On turn 1, if you have a mind vision, you might as well use it to see what Noth has in his hand. You will never use any of the cards he has in his deck anyway and you won't waste your 1 mana. Never drop Northshire Cleric on turn 1. The only time i would find this acceptable is if you know you can get some card draw out of it pretty fast and you can suicide it before turn 4-5. You shouls probably also have a Shadow Word Death in hand if you decide to play Cleric on turn 1.

On turn 2, play Lightwell. If you don't have it yet, remove Noth's stuff with what you have, but you're on a clock now to either draw Lightwell or Lightspawn pretty fast.
As soon as Lightwell is down, you can pretty much stay at 30 health until turn 5 where Noth starts to drop abominations and Spectral Knights. Don't waste your silences on things that are not dangerous. An unstable ghoul forms no threat if you only have a Lightwell out.
When your Lightwell or Lightspawn is down, just keep it alive and wait for your combo to kick off.

As with all heroic fights, you need a bit of RNG on your side. It took me 4 tries with this deck, and on each of my 3 losses, i had him pretty close to death.