What do you want to know? What to spec? What stats to go for?
You need Phys % damage, Boost to Fan of Knives %, Grenade/Bolas %.
Sash of Knives is a great legendary to start with.
Also, you'll need a sick 1H and Shield. I recommend getting anything that has a proc (snicker, thunderfury). Shard of Hate is amazing for the class. Coven's Criterion is probably the best shield for a melee DH (I have one).
Use Vault, Shuriken Cloud, and two other abilities (your choice). Primary is Grenades/Bolas, Secondary is Fan of Knives (the rune that makes it a hatred spender).
I personally use Vengeance + Seethe for Hatred regen, and Companion(Wolf) for extra 30% damage buff. Currently using Vault with Arrows rune because they're physical and auto crits.
Passives are Blood Vengeance (SO GOOD), Tactical Advantage (placement is key on a melee DH, as is running away from death), Cull the Weak (a FOK with a FOK right after it does double damage, you can cast two within the span of a second), and Ambush. Ambush makes it so the whites pretty much explode on two FOK hits.