Here is a list of all Skinning Trainers I could find for both factions. Please remember, if the coordinates are off a bit, it's becaue I relied heavily on contributions from others. The information should get you close to them any way.
The Names are in alphabetical orer, but their locations are highlighted for ease.
Hope this helps.
Skinning Trainers for Horde and Alliance
Alliance
Balthus Stoneflayer – in Ironforge, NW corner of the Great Forge (Trains Apprentice, Journeyman, Expert and Artisan)
Eladriel – Darnassus, NE Corner of bottom level (Trains Apprentice, Journeyman, Expert and Artisan)
Gurf – Azuremyst Isle, South of the center of Stillpine Hold (Trains Apprentice, Journeyman, Expert and Artisan)
Helene Peltskiner – Goldshire, Cabin NE of town , next to the road (Trains Apprentice, Journeyman, Expert and Artisan)
Jayla – Ashenvale, Silverwind Refuge (Coord 50, 66) - (Trains Artisan)
Jelena Nightsky – Hellfire Peninsula, Honor Hold – (trains all levels)
Maris Granger – Stormwind – Old Town (About 68, 48) (Trains Apprentice, Journeyman, Expert and Artisan)
Radnaal Maneweaver – Teldrassil – South of the Oracle Glade, about coords 42, 50 (Trains Apprentice, Journeyman, Expert and Artisan)
Remere – The Exodar, Trader’s Tier – SE Corner of Exodar (Trains Apprentice, Journeyman, Expert and Artisan)
Wilma Ranthall – Easternmost part of Redridge Mountains (outside Lakeshire) – About coords 88, 71
Horde
Dranh – Camp Taurajo Tent by the Flight Path -(Trains Apprentice, Journeyman, Expert and Artisan)
Killian Hagey – Undercity – Western Edge of Rogues Quarter - (Trains Apprentice, Journeyman, Expert and Artisan)
Kulleg Stonehorn – Feralas – Camp Mohache - (Trains Apprentice, Journeyman, Expert and Artisan)
Malux – Desolace – Shadowprey Village – (Trains Artisan)
Matheryn – Silvermoon City – Outside town near FP, (coords about 53, 50) (Trains Apprentice, Journeyman, Expert and Artisan)
Mooranta - Thunder Bluff - (Trains Apprentice, Journeyman, Expert and Artisan)
Moorutu – Hellfire Peninsula – Thrallmar – (Teaches all levels)
Rhand Robart – Tirisfal Glades – Camp by road, east of UC next to road (Trains Apprentice, Journeyman, Expert and Artisan)
Thuwd – Orgrimmar – NE Edge of the Drag, about 63, 45 (Trains Apprentice, Journeyman, Expert and Artisan)
Tyn – Silvermoon City – Walk of Elders – about 64, 80 (Trains Apprentice, Journeyman, Expert and Artisan)
Yonn Deepcut – Mulgore – Thunderhoof Village – about coords 45, 57 (Trains Apprentice, Journeyman, Expert and Artisan)
BOTH FACTIONS:
Seymour – Shattrath City, Lower City, around 65, 68 (Trains Master only)
The Names are in alphabetical orer, but their locations are highlighted for ease.
Hope this helps.
Skinning Trainers for Horde and Alliance
Alliance
Balthus Stoneflayer – in Ironforge, NW corner of the Great Forge (Trains Apprentice, Journeyman, Expert and Artisan)
Eladriel – Darnassus, NE Corner of bottom level (Trains Apprentice, Journeyman, Expert and Artisan)
Gurf – Azuremyst Isle, South of the center of Stillpine Hold (Trains Apprentice, Journeyman, Expert and Artisan)
Helene Peltskiner – Goldshire, Cabin NE of town , next to the road (Trains Apprentice, Journeyman, Expert and Artisan)
Jayla – Ashenvale, Silverwind Refuge (Coord 50, 66) - (Trains Artisan)
Jelena Nightsky – Hellfire Peninsula, Honor Hold – (trains all levels)
Maris Granger – Stormwind – Old Town (About 68, 48) (Trains Apprentice, Journeyman, Expert and Artisan)
Radnaal Maneweaver – Teldrassil – South of the Oracle Glade, about coords 42, 50 (Trains Apprentice, Journeyman, Expert and Artisan)
Remere – The Exodar, Trader’s Tier – SE Corner of Exodar (Trains Apprentice, Journeyman, Expert and Artisan)
Wilma Ranthall – Easternmost part of Redridge Mountains (outside Lakeshire) – About coords 88, 71
Horde
Dranh – Camp Taurajo Tent by the Flight Path -(Trains Apprentice, Journeyman, Expert and Artisan)
Killian Hagey – Undercity – Western Edge of Rogues Quarter - (Trains Apprentice, Journeyman, Expert and Artisan)
Kulleg Stonehorn – Feralas – Camp Mohache - (Trains Apprentice, Journeyman, Expert and Artisan)
Malux – Desolace – Shadowprey Village – (Trains Artisan)
Matheryn – Silvermoon City – Outside town near FP, (coords about 53, 50) (Trains Apprentice, Journeyman, Expert and Artisan)
Mooranta - Thunder Bluff - (Trains Apprentice, Journeyman, Expert and Artisan)
Moorutu – Hellfire Peninsula – Thrallmar – (Teaches all levels)
Rhand Robart – Tirisfal Glades – Camp by road, east of UC next to road (Trains Apprentice, Journeyman, Expert and Artisan)
Thuwd – Orgrimmar – NE Edge of the Drag, about 63, 45 (Trains Apprentice, Journeyman, Expert and Artisan)
Tyn – Silvermoon City – Walk of Elders – about 64, 80 (Trains Apprentice, Journeyman, Expert and Artisan)
Yonn Deepcut – Mulgore – Thunderhoof Village – about coords 45, 57 (Trains Apprentice, Journeyman, Expert and Artisan)
BOTH FACTIONS:
Seymour – Shattrath City, Lower City, around 65, 68 (Trains Master only)