It's Tauren time guys! Again, I am not well versed on the Horde side of things since I mainly play alliance but I did not want our Horde friends to feel left out or forgotten so I'm giving it a go.
When you zone in our your Tauren you will find yourself in Camp Narache. The Tauren are not part of the questing exemption, so right from the start you need to be grinding your hooves off.
I suppose your best bet would be to head for Thorsnarl. Killing the Bristlebacks there will get your humanoid killing spree off to a good start. Sure they are only dropping a couple of copper but they are low level and so are you. Any money will help get you started at this point since you are penniless. There are also some young Battleboars milling about that will drop some Tough Jerky so if you want to get some free food you might as well kill a few of those as well. You can also visit the Battleboar Pen. The boars up there are level 4 and I killed them for a level and half and got 4 chipped boar tusks worth 38 copper a piece and two stacks of Tough Jerky. Keep one stack for emergency food, sell the other.
When you hit level 5, it's time to mooove (ed: blegh) on and head down into Mulgore. Bloodhoof Village is where I set up shop for the time being. Change your hearthstone at the inn, learn your First Aid, clear out your bags and buy an extra 6 slot back if you have the money. If not, then hang in there we'll either get the money to soon, or find a rare that may give us one instead.
Now the question becomes where do we go next? This zone is pretty big, with lots of ground to cover. I am not going to cover all the possible grind areas or we'll be here for a good long while. Therefore I'll just go over the spots I made some stops at to grind for a bit before moooving on.
The Winterhoof Water Well was my first stop. Several humanoid mobs here, plus some beasts surrounding it. The mobs here were in the level 6 range so totally doable for a level 5. The Thunderhorn Water Well is another quick stop, not many mobs right at the well but still humanoids to kill. There is a rare pink tallstrider that walks around the base of Mulgore so don't forget to check for it while over that way. While I was searching for the rare pink bird, I did come across a rare lion in The Golden Plains named The Rake. He did not give me a bag, but he did drop a green.
Windfury Ridge is another possible grind spot for some humanoid action, though I would save this till level 8 or 9 these mobs do have some level 10s mixed in so might be a bit tougher for some classes to take them on too soon.
If you are looking for another quick humanoid stop then don't foget to check in at the Wildmane Water Well. Again not many mobs but nice for a quick kill and go.
If you didn't get enough harpy action over at Windfury Ridge then head west/north west of Thunder Bluff to find some more harpies. Couldn't find a name for the exact area just head for the scraggly looking trees on the map. More harpies can be found just up into the hills from where The Darkmoon faire would set up camp near Thunder Bluff as well.
Honestly, these rolling hills of Mulgore are just so beautiful to take in I think it would actually be better to take a killing tour around the zone then to restrict yourself to one or two places. There is so much to kill here, just jump in and go for it. Work your way around the whole zone (I wouldn't recommend going in caves and since you'll be moving around a lot), just keep an eye on your mob levels so you don't get into a fight that you can't handle too soon. There are a few yellow mobs that are level 12 (a few kodos), so just be careful and have fun.