1,400 x Knothide Leather
80 x Thick Clefthoof Leather
On top of this, you’ll need some threads and other materials that can be purchased from leatherworking vendors.
Leatherworking 1 to 300
First things first, you’ll need to head to one of the major cities and learn apprentice leatherworking from a trainer. Depending on your faction, just head to one of the hub cities (Orgrimmar, Stormwind City, etc.) and find the trainer. As you progress, you’ll need to come back to these trainers to continue progressing.
Once you hit 125, you’ll need to go to either Darnassus (Alliance) or Thunder Bluff (Horde) and reach level 20 to learn expert leatherworking. You’ll need to then hit level 35 and head to either the Hinterlands (Alliance) or Feralas (Horde) to learn artisan leatherworking to level past 200. That said, here is a general guide for getting to level 300.