If you choose herbalism as your profession in the World of Warcraft, you will need to collect some herbs for further use. Here is the herb list for you:

To start with you will be picking Peacebloom, Silverleaf, and Earthroot (skill 15,) until you are at least skill level 50.

The 10-20 area herbs, found in the Ghostlands, Durotar, Silverpine, Westfall, and Redridge, are: Peacebloom, Silverleaf, and Earthroot, Mageroyal (requires skill 50,) Briarthorn (70,) Stranglekelp (85 and take a water breathing potion,) and Bruiseweed (skill 100.)

In the 18-30 areas (Duskwood, Hillsbrad, and the Wetlands) you'll find Mageroyal, Briarthorn, Stranglekelp, Bruiseweed, Wild Steelbloom (115,) Gravemoss (120,) Kingsblood (125,) and Liferoot (150.) The Grave Moss can be found in and around, you guessed it, graveyards.

Next up are the 30-40 areas: The Alterac Mountains or Arathi Highlands are next. Here's what you'll find: Stranglekelp, Bruiseweed, Wild Steelbloom, Gravemoss, Kingsblood, Liferoot, Goldthorn (170,) Khadgar's whisker (185,) and maybe Wintersbite at 195. Stranglethorn Vale, The Badlands, and Swamp of Sorrows are other good herb picking places at this level.

In STV and the Badlands you'll find Purple Lotus (210,) Badlands has Firebloom (205,) and the Swamp has Blindweed (235.) Firebloom (205.)

The 40 -50 zone: I went to The Hinterlands next, and then to the Eastern Plaguelands. In the Hinterlands you'll find Purple lotus (skill 210, in the troll ruins,) Ghost mushroom (caves, 245,) Golden sansam (260,) and Sungrass at 270. Killing the local trolls will also result in some Wildvine drops.

The last area in the Old Word (Azeroth) that you will need to work is the Eastern Plagelands. You will find a variety of herbs there and will probably hit 300 before doing a full loop of the zone. You'll find: Arthas' tears (220,) Sungrass (270,) Golden sansam (260,) Dreamfoil (270,) Mountain silversage (280,) and Plaguebloom (285.)

Ok, now you have your 300 skill and you're ready to hit the Outlands. Get Master Hebalist when you hit your side's main town in Hellfire (Thrallmar or Honor Hold) and then do a few loops around Hellfire Peninsula and then Zangamarsh. Unless you're hunting specific herbs you won't need to go beyond Zangamarsh to hit 375.

Various Motes (of life, shadow, etc.) sometimes appear when picking Outland herbs. That will come with your Outland Herb picking, particularly from the Felweed. Fel Lotus (which sells for a nice price) also has a small chance to drop from any of the Outland herbs. It's most commonly seen off of the Felweed, Dreaming Glory, Ragveil, and Flame Caps.