Recipeedit
From WoWWiki
A recipe lists a set of required ingredients that can make or produce an item depending on a required profession or class and a required level. This can be in the form of an item (like a note, parchment or scroll) or given by a trainer. When in the form of an item, they are sometimes found (in limited supply) on vendors throughout the world, or as drops from mobs. In the game manuals, they are sometimes called blueprints. Sometimes, a recipe improves the skill of a player's profession, such as increasing it from 300 to 375, rather than teaching the player to make another item. Basically, a recipe is a method for improving a profession. Below is a listing of different professions that uses item-recipes, what different recipes are called and what they looks / may look like.
Primary professions:
Mining recipes are books. There are only two of them in the game, one referred to as a 
guide and the other a 
study.
Blacksmithing recipes are 
scrolls called Plans. There are also six 
paper sheets referred to as "volumes" which all combined will give armorsmith-blacksmiths 3 plans for enchanted thorium-armor.
Tailoring recipes are scrolls called Patterns. There is also a 
book called "A Guide to Northern Cloth Scavenging" teaching a passive skill.
Leatherworking recipes are also scrolls called Patterns.
Engineering recipes are scrolls called Schematics. In rare cases they are called Plans.
Enchanting recipes are 
paper sheets called Formulas.
Alchemy recipes are scrolls called Recipes.
Jewelcrafting recipes are scrolls called Designs.
Inscription recipes are called Techniques. There is only four of them, one 
book and three scrolls. Many other glyphs are learned from books called [Book of Glyph Mastery] which works a little different than other recipes - each book may teach the scribe a random glyph chosen from 50 different kinds.
Secondary professions:
Cooking recipes are also called Recipes. Usually they are scrolls, but some are paper sheets and one a book.
First Aid recipes are books called 
Manuals, although one is called 
[Master First Aid - Doctor in the House] (notice that this book teaches the player higher skill in First Aid instead of an item). There is also a scroll called a Formula.
Fishing once used a few recipes being books that taught the player higher levels of fishing. There were only two of them, one called [Expert Fishing - The Bass and You] and the other 
[Master Fishing - The Art of Angling]. As of patch 3.1.0, new levels now are taught by trainers like in any other profession. In patch 2.3.0 however, there was implemented another 
book only obtainable by fishing. It teaches players an ability to find fish.
Class-specified profession(s):
Poisons were once a profession only known by Rogues, which allowed them to make their own poisons. Patch 3.0.2 removed this skill, having Rogues buy poison instead of making it. Only one recipe existed for this profession, [Handbook of Deadly Poison V]. Notice that the term "Handbook" and the item being a book in itself counts for several Rogue-abilities taught from items in general, and not as qualities for recipes especially in this profession. Some items teaching Rogue-abilties are also called "Manuals".
Recipe names are, to an extent, interchangeable. For example, it is not uncommon to see people referring to ANY recipe, be it jewelcrafting, alchemy, etc, as a "pattern", "plans", or "design".
Rarity of different recipes
Recipes often come in different colors (both picture and name), depending on their rarity. Although the system differs between different professions, a common rule is that recipes in white are "common" recipes that usually are bought from vendors, while any other colors are more uncommon recipes dropped by monsters or obtained from quests. Generally, the color of a recipe reflects the quality of the crafted item, and if the item is either unusual or powerful for its level, the recipe is often hard to obtain.
There are however several exceptions; some white cooking-recipes may for example be considered extremely rare even though they are bought for less than a gold from easily accessable vendors, or are rewards from simple low-level quests. This is because many cooking-recipes are only obtainable by players playing as a Horde-character and vice versa, thus only allowing the opposite faction to learn the recipe by selling it in the neutral auction house. Another phenomenon is rare recipes often selling for quite the price between players even though the crafted item may be next to useless; this is because many players devoted to their profession seek to complete it as much as possible, even with useless items. Before selling a recipe, players therefore should always check the market to see what people are willing to pay.
