First Aid

Horde

All (to 150)
Arnok (Valley of Spirits, Orgrimmar)
Mary Edras (The Rogues Quarter, Undercity)
Nurse Neela (Brill, Trisfal Glades)
Pand Stonebinder (Spirit Rise, Thunder Bluff)
Rawrk (Razor Hill, Durotar)
Vira Younghoof (Bloodhoof Village, Mulgore)

Expert (to 225)
Expert First Aid Book - Buy from Balai Lok'Wein in Brackenwall Village, Dustwallow Marsh

Artisan (to 300)
Quest: Triage - Doctor Gregory Victor (Hammerfall, Arathi highlands)

Master (to 375)
First Aid Manual - Sold by Aresella in Falcon Watch, Hellfire Peninsula

Alliance

All (to 150)
Byancie (Dolanaar, Teldrassil)
Dannelor (Craftsman's Terrace, Darnassus)
Fremal Doohickey (Menethil Harbour, Wetlands)
Nissa Firestone (The Great Forge, Ironforge)
Shaina Fuller (Catherdral Square, Stormwind City)
Michelle Belle (Goldshire, Elwynn Forest)

Expert (to 225)
Expert First Aid Book - buy from Deneb Walker in Stromgarde Keep, Arathi Highlands

Artisan (to 300)
Quest: Triage - Starts with Nissa Firestone (The Great Forge, Ironforge)

Master (to 375)
First Aid Manual - Sold by Burko in Temple of Telhamut, Hellfire Peninsula