A word on profession enchants
Many professions provide alternative enchants for a given slot or two that are better than the best option available to everyone who is not of that profession. You should always use these. In the past I left this advice at that and just listed the non-profession enchants, but always got tons of questions about the profession enchants.
So this time I'm going to try to include the profession-specific ones. I may forget a couple, and if I miss yours, just know that yes, profession-specific ones are better than the standards!
Delightfully in Mists of Pandaria we don't have any kind of helm enchant at all anymore. This is one less slot we need to worry about, so don't obsess about trying to find where to get it or what faction to get rep with. You don't need rep with any faction and you don't have any kind of helm enchant.
There is no enchant for the neck slot.
The Tiger Claw Inscription, available from scribes, is the should enchant for hunters. In past expansions we had to grind rep with some faction to get the privilege of buying our should enchants from them. No more rep needed for our enchants. Yay!
Inscriptionists themselves have an even better profession-only version they can use: Secret Tiger Claw Inscription.
We have two possible options for our back enchant, both coming from your friendly guild enchanter (or the AH if the guild enchanter isn't so friendly): the Enchant Cloak – Accuracy if you are in need of additional hit rating, and Enchant Cloak – Superior Critical Strike if you don't need the hit.
Keep in mind you're aiming for 2,550 hit rating for the raid hit cap (2,210 if you're a space goat) and enchanting this slot into hit is a good idea if you need the help getting there.
Tailors have a better profession-specific version they can use instead: Swordguard Embroidery.
Engineers will want to add the Cloak Tinker: Goblin Glider on in addition to the standard enchant. It won't boost your DPS, but it's totally awesome.
The new Mists chest enchant is Enchant Chest – Glorious Stats, created by enchanters.
Our preferred wrist enchant is Enchant Bracer – Greater Agility, also created by enchanters.
Leatherworkers will want to use the profession-specific Fur Lining – Agility instead.
We actually have three options for hands that are very close to each other in DPS contribution. The winner by a slight edge is Enchant Gloves – Superior Expertise. The advantage of this enchant is that even if you don't need the expertise, you can free up some of your reforging to allow you to reforge a less desirable stat into crit (instead of using it to reforge into expertise). So in a way this enchant is actually getting you critical strike rating, which is a bit better than haste or mastery.
That said, particularly for BM, mastery is darned near as good as crit (or possibly as good depending on your specific gear) so Enchant Gloves - Superior Mastery isn't much worse, particularly if you're at the expertise cap without reforging.
Engineers will want to use their Synapse Springs on the hands slot. If you want life to be easy you can macro these into your shots; if you want to squeeze every last ounce of DPS out you will manually activate them at the most opportune time, while other advantageous procs/buffs are happening.
Once again we go with the blacksmithing-provided Living Steel Buckle for our waist slot, and we want to put only Delicate Primordial Ruby into that extra slot (not even an epic hybrid gem).
Engineers can add Watergliding Jets in addition to the blacksmithing gem socket, though I'm pretty underwhelmed by it.
All hunters will want to slap the Shadowleather Leg Armor onto their legs. This is created by leatherworkers, and it's worth noting that they can also make a weaker version of the leg armor (referred to a Tier 1). If that's the only one you can get your hands on, well, then you gotta work with what you got.
Leatherworkers themselves will want to use the profession-specific Primal Leg Reinforcements.
Our boots enchant is provided by enchanters and is the delightful Enchant Boots – Blurred Speed providing us both agility and a small movement speed boost (that does not stack with other effects, by the way). It's awesome.
There is no enchant for the ring slot.
There is no enchant for the trinket slot.
Engineers again provide our ranged weapon enchant in the form of the badass Lord Blastington's Scope of Doom. This scope procs an absolutely huge agility boost. If you really want to get tricksy you can track the proc via Power Auras or your favorite tracking addon so that you can stack other abilities with the proc for a mulitplicative bonus (adding any stat boost to an agility boost is a multiplicative gain).
Scattered Shots is dedicated to helping you learn everything it takes to be a hunter. If you're stuck in one of the nine support classes, why not move up to the big league and play a hunter?