Hearthpwn

This deck mainly focuses around using healing a draw spells to cycle through your deck and keep you alive to the point where you opponent runs out of steam, and has trouble dealing damage. Yogg-Saron, Hope's End is you main win condition, however using the available resources like Blessing of Kings and Keeper of Uldaman can also enable you to win just using your hero power and Stand Against Darkness.

Mulligan:

Your starting hand tends not to matter, as long as you have some cheap cards to play, such as Holy Light [/card]or [card]A Light in the Darkness. Try to keep Brann Bronzebeard out of your starting hand and save him for later, but if you feel the need to play him do so, however it is not recommended.

Matchups:
Most matchups are fine, you can easily deal with aggro decks using Consecration and the many healing spells, and just keeping 1/1's on the board to buff with Blessing of Kings. The most difficult matchup is mage, especially Freeze/Yogg mage, as the hard removal cards that clear Ragnaros, Lightlord and Tirion Fordring, which can be a problem for surviving the late game.

Extra Bit:

I have tried to use Malygos in the deck is place of one Keeper of Uldaman, and it works quite well, but it is not as good as early game control is alot harder that way, but surviving the late game is easier.