Guides about Leatherworking and Skinning.
This guide assumes that you are in Stormwind and using the Trainer in Olde Town, and then when neccesary, you will travel to Darnassus, Craftsmans Terrace.
This guide will take you to 240 in an extremely effective manner.
1-45 Light Leather Kits (~49 Light Leather)
45-55 Handstitched Cloaks (~32 LL)
55-100 Embossed Leather Gloves (~141 LL)
100-123 Fine Leather Belts (~174 LL)
123-137 Dark Leather Boots (~64 Medium Leather)
138-155 Dark Leather Pants (~288 ML)
155-165 Hillsman Gloves (~140 ML)
165-180 Heavy Leather Kits (~95 Heavy Leather)
180-183 Hillsman Gloves (~98 ML)
183-191 Barbaric Shoulders (~64 HL 8 Cured Heavy Hides)
191-196 Barbaric Harness (~70 HL 5 Iron Buckles)
196-206 Dusky Bracers (~ 160 HL)
206-220 Thick Leather Kits (~70 Thick Leather (Save 6 of these for quest))
220-225 Night Scape Head Bands (~25 TL (Save 2 for quest))
225-227 Turtle Scale Breastplate (~12 TL 24 Turtle Scales) (Quest)
227-229 Turtle Scale Gloves (~12 TL 16 TS) (Quest)
229-230 Night Scape Tunic (~14 TL) (Quest)
230-232 Night Scape Head bands (~20 TL)
232-233 Turtle Scale Bracers (~16 TL 24 TS) (Quest)
233-235 Turtle Scale Helm (~28 TL 48 TS) (Quest)
235-237 Night Scape Pants (~ 28 TL) (Quest)
237-240 Night Scape Boots (~ 32 Tl) (Quest)
Ok so I think that covers it the Numbers listed to the right of the recipe, is the number of leathers and Scales and Buckles it should take to complete the recipes.
If there are any problems, let me know
PSYON
Journeyman
Expert
Artisan
Master (you have to make a quest to become Artisan)
Journeyman
Expert
Artisan
Master
Skinning Level = 1 - Your Level = 5
Horde
Undead = Hounds around Brill
Orcs and Trolls = Mottled Boars and Scorpids around Sen'Jin Village
Tauren = Prowlers and Plainstriders around Bloodhoof Village
Alliance
Humans = Boars around Goldshire
Gnomes and Dwarfves = Crag Boars and Wendigo's South of Kharanos
Night Elves = Nightsabers and critters around Dolanaar
Skinning Level = 25 - Your Level = 10
Horde
Undead = Worgs and Moonrage Gluttons around Silverpine
Orcs and Trolls = Boars, Scorpids, Crocolisks and Raptors around Orgrimmar
Tauren = Prowlers and Praire Wolves around Thunderbluff
Alliance
Human = Prowlers and Bears around Eastvale Logging Camp
Gnomes and Dwarfves = Wolves around Brenwall Village.
Night Elves = Moonstalkers and Bears around Auberdine
Skinning Level = 50 - Your Level = 13
Horde
(at this level most Horde should be heading towards XR)
Plainstriders, Raptors and Prowlers around XR
Alliance
Humans = Goretusks all around Sentinel Hill.
Gnomes and Dwarfves = Bears and Crocolisks around Thelsamar
Night Elves = Moonstalkers and Bears North of Auberdine
Skinning Level = 100 - Your Level = 20
Horde
Stormsnouts and Thunderhawks around Camp Taurajo
Alliance
(at this level most Alliance should be heading for The Wetlands)
Crocolisks and Raptors around Bluegill Marsh and Whelgar's Excavation Site
Alternatives
Whelps and boars around Lakeshire for Alliance.
Skinning Level = 130 - Your Level = 24
Alliance and Horde
Bears and Mountain Lions around Hillsbrad Foothills
Alternatives
Ravagers and Wolves in Duskwood if your Alliance.
Bears, Stags and Ghostpaws in Ashenvale.
Skinning Level = 150 - Your Level = 28
Alliance and Horde
Yeti Cave in Hillsbrad Fields and Mountain Lions on the "Daggers" (these are the bits of land between Hillsbrad and Alterac Mountains, one is called Corrans Dagger, so hence the nickname)
Alternatives
Hyenas, Lions, Wyvern and Thunderhawks in Thousand Needles.
Bears, Stags and Ghostpaws in Ashenvale.
Skinning Level = 170 - Your Level = 32
Alliance and Horde
Raptors in Arathi Highlands.
Alternatives
Turtles and Basilisks in The Shimmering Flats.
Skinning Level = 180 - Your Level = 34
Alliance and Horde
Raptors, Panthers and Tigers around Nessingwarys Camp in Stranglethorn Vale
(you could actually get your skinning level all the way to 300 in and around STV as the mobs range from level 34 to level 50)
Alternatives
Raptors and Crocs in Dustwallow Marsh.
Thunder Lizards, Kodos, Basilisks, Scorpids and Hyenas in Desolace.
Whelps in Swamp of Sorrows.
Skinning Level = 220 - Your Level = 38
Alliance and Horde
Raptors and Gorillas around the Gurabashi Arena
Alternatives
Panthers, Jaguars and Crocs in Swamp of Sorrows.
Dragonkin, Coyotes and Ridge Stalkers/Huntresses in Badlands.
Wolves around Feathermoon Stronghold in Feralas if your Alliance.
Skinning Level = 250 - Your Level = 45
Alliance and Horde
Snickerfangs and Boars in North Blasted Lands
Alternatives
Silvermanes and Gryphons in The Hinterlands.
Stags and Hippogryphs in Azshara.
Hippogryphs, Apes, Bears, Wolves, Screechers and Yetis in Feralas.
Skinning Level = 275 - Your Level = 50
Alliance and Horde
Jagueros and Gorillas on Jaguero Island (Large Island to the East of Booty Bay where Princess Poobah is being held). Skin till 300.
Alternatives
Yetis, Chimeras and Bears in Winterspring.
Bears in Western Plaguelands.
Plaguehounds and Plaguebats in Eastern Plaguelands.
Turtles by Raventusk Village in The Hinterlands.
Turtles and Chimeras in Azshara.
Dragonkin, Worgs and Scorpids in Burning Steppes.
Thought I'd add the mob levels that you can expect to get each specific leather from.
Ruined Leather Scraps: 1-16
Light Leather: 1-27
Light Hide: 10-27
Medium Leather: 15-36
Medium Hide: 15-36
Heavy Leather: 25-46
Heavy Hide: 25-46
Thick Leather: 35-63
Thick Hide: 40-59
Rugged Leather: 43-63
Rugged Hide: 47-63