Talk to Haedrig Eamon, the blacksmith. You tell Haedrig that Deckard sent you and ask him to help you find the crown of Leoric. But Haedrig has a different problem. His wife is locked in the cellar, like all those who have been bitten. He needs to put them all down. But how can he kill his own wife?

"What cruel compassion led the villagers to lock away those loved ones and friends who were doomed to turn and join the numbers of the risen dead. They have given Haedrig the task of ending their lives, but it is an impossible thing to ask of a person. I will help him do what he must, for bringing death in such a manner is something that I have done and can do again"

This gives you your next objective: You need to Kill the Ravenous Dead in the Cellar of the Damned. Follow Haedrig to the cellar. If you lose him, just head towards the blinking yellow circle on the mini map. Enter the Cellar of the Damned. Break open one of the doors, then kill the Ravenous Dead there. Then, kill his wife, Mira Eamon.

Haedrig thanks you for helping him. You ask him about the Crown of Leoric. He tells you that it is buried with his chancellor - Haedrig's grandfather. You'll find the tomb in a cemetery in the Weeping Hollow. Haedrig also asks that you look for his apprentice who went in there too.

"Haedrig told me that the crown of the Skeleton King lies in the tomb of his chancellor, who was one of Haedrig's ancestors. My course is now clear"

Pick up any loot in the Cellar, then go back up to New Tristram. You objective now is to open the Northwest Gate. A big pack of Scavengers comes and attacks you, kill them and cross the bridge. Then you need to Find the Cemetery of the Forsaken in the Weeping Hollow. Start going north, fighting Ravenous Dead, Grotesques, Hungry Torsos, Corpse Worms, and other monsters. There are some Defiled Graves along the way, but be careful since a lot of monsters spawn from those if opened. If you are slain, you will revive at your last checkpoint.

You could also run into an elite Yellow Boss here, Nightmarish Shakal the Cursed. He attacks you with powerful melee attacks so watch your health. Anoother Elite you can encounter is Grule the Damned (Knockback). When you kill them, you might get the following achievement (depending on how many bosses you have killed so far):

Elite Kills (5)
Killed 5 elite monsters (champions, rares or uniques)

Diablo 3 Cemetery of the Forsken in the Weeping Hollows

The rest of the way to the Cemetery will continue to be swamped with undead, so tread carefully. Go towards the Northeast. Eventually you see a yellow arrow on the minimap directing you to your destination, which changes to a blinking yellow circle as you approach it. The tombstones around you tell you that you have reached the Cemetery. Open the gate and enter the Cemetery of the Forsaken.