What to expect:
70k+ XP/hr
Plenty of Crystals, Health Items and Crafting Materials

Recommended skills:

Freeze, Lightning Strike & Protection Aura (Switch out for Damage spell if you can survive without PA)

I've found that, at least for early game (~lvl 5-12), farming Graveyard yields a good amount of both experience and loot.

You have a big number of elites spawning in here (200 XP per kill) and they all drop decent loot.

First time you enter there are a few secrets to unveil which give a nice 100 XP each.

With stray trash mobs and all the elites you're looking at around 1500-2500 experience gained per run. That along with Crystals, Healing Items and some Crafting Materials. Each run should take around 1,5 minutes to complete. (Depending on your damage, survivability, spawn points etc.)

All in all a very simple run to do. Once you've cleared the area, Exit to Map and re-enter the Graveyard.

Mind you that you might want to progress further in the story to upgrade your gear to make this even faster.