This guide is meant for either an individual or a guild that is interested in finding efficiencies while leveling multiple professions at the same time. By using the interdependencies of the different professions, you can make the process of leveling these professions less expensive and time consuming than by doing them one at a time.
You have two options when it comes to creating a set of characters. With the first option, each crafting profession is paired with the most appropriate gathering profession:
1) Mining, Jewelcrafting
2) Mining, Blacksmithing
3) Mining, Engineering
4) Skinning, Leatherworking
5) Tailoring, Enchanting
6) Herbalism, Alchemy
Or, if you are opposed to having so many characters, you could have the following arrangement:
1) Tailoring, Jewelcrafting
2) Mining, Engineering
3) Leatherworking, Skinning
4) Enchanting, Blacksmithing
5) Alchemy, Herbalism
In any case, your first step after creating your characters will be to level them up to about 10 and get them to a major city. Once in the city, train with the appropriate professions and buy any necessary gathering equipment (i.e. Mining Pick, Skinning Knife). Now that you have your gathering equipment, it's time to get out there and gather!
Apprentice
When you first start off at level 10, it is probably best to keep leveling and gather as you go. If you need help leveling, I recommend either Joana's Leveling Guide for Horde or Brian Kopp's Leveling Guide for Alliance. Once you get to level 20 you should be high enough to do some gathering runs. To find mining nodes and herbs, I recommend MapWoW. Leather can be skinned from most beasts you come across, and Cloth drops from most humanoids. To find drop rates for items, you can do a search on Allakhazam. Once you've gathered everything you'll need to buy any rare materials that you didn't get or vendor items needed for the round of crafting you're about to do. (N.B. Always be thinking about your Enchanter. Anything green or better you make that won't sell well at the Auction House should be sent to your Enchanter for Disenchanting.)
Materials to Gather
?? 264 Copper Bar
?? 210 Rough Stone
?? 60 Tin Bar (to make Bronze)
?? 35 Light Leather
?? 20 Light Hide
?? 160 Linen Cloth
?? 60 Peacebloom
?? 60 Silverleaf
Materials to Buy
?? 20 Tigerseye
?? 14 Weak Flux
?? 10 Wooden Stock
?? 75 Coarse Thread
?? 1 Copper Rod
?? 1 Strange Dust
?? 1 Lesser Magic Essence
?? 60 Empty Vial
Jewelcrafting
1-20
Delicate Copper Wire
40 Copper Bar
(keep for Tigerseye Bands)
20-30
Rough Stone Statue
80 Rough Stone
30-50
Tigerseye Band
(buy 20 Tigerseye, send extras to Enchanter for DE)
50-75
Bronze Setting
60 Bronze Bar
(keep for Pendant of the Agate Shield)
Blacksmithing
1-25
Rough Sharpening Stone
50 Rough Stone
25-45
Rough Grinding Stone
40 Rough Stone
(keep 25 for Silver Rods)
45-75
Copper Chain Belt
120 Copper Bar
Engineering
1-40
Rough Blasting Powder
40 Rough Stone
40-50
Handful of Copper Bolt
10 Copper Bar
(keep for Rough Broom Sticks)
50-51
Arclight Spanner
6 Copper Bar
51-65
Copper Tubes
28 Copper Bar
(buy 14 Weak Flux, keep 10 Copper Tubes for Rough Broom Sticks)
65-75
Rough Broom Stick
(buy 10 Wooden Stock)
Leatherworking
1-35
Light Armor Kit
35 Light Leather
35-55
Cured Light Hide
20 Light Hide
(keep 15 for Fine Leather Tunic)
Tailoring
1-50
Bolt of Linen Cloth
160 Linen Cloth
(keep for Linen Bags and Reinforced Linen Cape)
50-70
Linen Bag
(buy 60 Coarse Thread)
70-75
Reinforced Linen Cape
(buy 15 Coarse Thread)
Enchanting
1-2
Runed Copper Rod
(buy 1 Copper Rod, 1 Strange Dust, 1 Lesser Magic Essence) 2-75
Enchant Bracer - Minor Health
(always Disenchant for experience first)
Alchemy
1-60
Minor Healing Potion
60 Peacebloom, 60 Silverleaf
(buy 60 Empty Vial, keep 50 for Lesser Healing Potions)