This is the best alchemy guide i could find. The author is not stated in the website i took this guide. I think i will list all alchemy leveling resource i could find some other time.

World of Warcraft Alchemy 1-300 Guide

This guide will show you how to get your alchemy skill up from 0 to 300. The guide will only use recipe's available at a trainer until 265 and vendor available recipe's from 265 to 300.

This guide only uses recipes that require herbs and vendor bought material (vials).

This guide does not tell you how to get all the different recipe's from quests, vendors or drops. What you do once you hit 300 is entirely up to you. This guide will not tell you what to do with the potions you make either.

This guide is primarily aimed at those who want to switch profession at high level or have high level alts, friends or guildmembers.

Preparation

You are going to need a lot of herbs. Create an alt storage character to store these herbs and then farm (or have an alt farm) for the herbs needed. Use the ingame mail system to send the herbs to the storage character. Don't forget to send some gold to the storage character, so she can send the herbs back.
Once you have all the components collected, everything has to be send back to your main character. The mailbox only shows the first 50 items you have in the mail. It also puts the last item send to you on top. So to avoid complications send the components you need first last: i.e peacebloom and silverleaf are needed first, so these are the last to be send back to your main, after the briarthorn, mageroyal, etc.

The recipe's used require vendor bought components such as vials. These cost gold. To learn recipe's from a trainer also costs gold. The amount of gold needed is aproximately 40 to 50 gold if you farm all of the herbs. If you want to buy everything you need from the auction house expect to spend upwards to 225 gold. This does not include gold for recipe's from vendors or the auction house.
Below is a table that shows the amount of herbs needed. The minimum amount column shows the minimum amount needed if you would get a skill point every time you make something. However at some point a recipe will be yellow or even green when you make something so you won't allways get a skill point. The estimated amount column deals with this, so try to get the estimated amount of herbs on your storage character. If you are buying all the herbs you need from the auction house, I suggest getting the minimum amount and only buy more when needed.


Component Minimum Amount Estimated Amount

Peacebloom 60 (3 stacks) 60 (3 stacks)
Silverleaf 60 (3 stacks) 60 (3 stacks)
Mageroyal 15 (1 stacks) 20 (1 stacks)
Briarthorn 80 (4 stacks) 90 (5 stacks)
Stranglekelp 40 (2 stacks) 50 (3 stacks)
Bruiseweed 30 (2 stacks) 35 (2 stacks)
Wild Steelbloom 5 (1 stacks) 10 (1 stacks)
Kingsblood 30 (2 stacks) 40 (2 stacks)
Liferoot 30 (2 stacks) 40 (2 stacks)
Goldthorn 45 (3 stacks) 50 (2 stacks)
Khadgar's Whisker 15 (1 stacks) 20 (1 stacks)
Sungrass 60 (3 stacks) 70 (4 stacks)
Blindweed 30 (2 stacks) 35 (2 stacks)
Arthas' Tears 20 (1 stacks) 25 (2 stacks)
Golden Sansam 40 (2 stacks) 60 (3 stacks)
Mountain Silversage 20 (1 stacks) 30 (2 stacks)


Getting from 1 to 50

Getting from 1 to 50 is easy enough. Make 60 minor healing potions. This should get you to skill 60. You need at least skill 55 for the next step, so don't worry if you didn't get to 60. Keep the minor healing potions, you will need them later.
Once you hit 50 talk to the appropriate trainer to become Journeyman Alchemist. You have to be level 10 to become Journeyman Alchemist.
This table shows the different recipes used to get from 0 to 50.

Skill Item From - To

1 Minor Healing Potion 0 - 60 (60)


Getting from 50 to 125

Use the minor healing potions made earlier to make lesser healing potions to get to 110. If you didn't reach 110, make elixirs of wisdom until you do.
At 110 you can train the healing potion recipe. Make those until skill 125
Once you hit 125 talk to the appropriate trainer to become Expert Alchemist. You have to be level 20 to become Expert Alchemist.
This table shows the different recipes used to get from 50 to 125.


Skill Item From - To

55 Lesser Healing Potion 60 - 110 (50)
90 Elixir of Wisdom 105 - 110 (5)
110 Healing Potion 110 - 125 (15)


Getting from 125 to 200

Make some more healing potions to get to skill 140. Make lesser mana potions to get to 155, greater healing potions to get to 185 and elixirs of agility to get to 200.
Once you hit 200 talk to the appropriate trainer to become Artisan Alchemist. You have to be level 35 to become Artisan Alchemist.
This table shows the different recipes used to get from 125 to 200.


Skill Item From - To

110 Healing Potion 125 - 140 (15)
120 Lesser Mana Potion 140 - 155 (15)
155 Greater Healing Potion 155 - 185 (30)
185 Elixir of Agility 185 - 200 (15)


Getting from 200 to 265

Make some more elixirs of agility to get to 210. Make elixirs of greater defense until 215 and then make superior healing potions until 230. Make elixirs of detect undead to get to 250 and elixir of greater agility to get to 265.
This table shows the different recipes used to get from 200 to 265.


Skill Item From - To

185 Elixir of Agility 200 - 210 (10)
195 Elixir of Greater Defense 210 - 215 (5)
215 Superior Healing Potion 215 - 230 (15)
230 Elixir of Detect Undead 230 - 250 (20)
240 Elixir of Greater Agility 250 - 265 (15)


Getting from 265 to 300

Although you can get to 300 using the elixir of detect demon recipe, the gromsblood needed is expensive when bought from the auction house so i decided to use vendor available recipe's to get from 265 to 300.
Get the superior mana potion recipe from Ulthir in Darnassus or Algernon in Undercity and the major healing potion recipe from Evie Whirlbrew in Everlook.
Make superior mana potion to get to skill 285 and major healing potions to get to 300.

Congratulations, you now have 300 skill in alchemy.

This table shows the different recipes that are avaible through vendors to get from 265 to 300.

Skill Item From - To
260 Superior Mana Potion 265 - 285 (20)
275 Major Healing Potion 280 - 300 (20)

This table shows who and where the different vendors are for the previously mentioned recipe's.

What Who Where
Superior Mana Potion Ulthir (Alliance Faction)
Algernon (Horde Faction) Darnassus
Undercity
Major Healing Potion Evie Whirlbrew (Neutral) Everlook in Winterspring