Engineering

Horde

Apprentice (to 75)
Graham Van Talen (The Rogues Quarter, Undercity)
Mukdrak (Razor Hill, Durotar)
Thund (Valley of Honour, Orgrimmar)
Tinkerwiz (Ratchet, The Barrens)
Twizwick Sprocketgrind (Venture Co Mine, East Mulgore)

Journeyman (to 150)
Franklin Lloyd (The Rogues Quarter, Undercity)
Nogg (Valley of Honour, Orgrimmar)

Expert (to 225)
Roxxik (Valley of Honour, Orgrimmar)

Artisan (to 300)
Buzzek Bracketswing (Gadgetzan, Tanaris)
Gnome Engineering Quest - Starts with Tinkerwiz (Ratchet, The Barrens)
Goblin Engineering Quest - Starts with Nixx Sprocketspring (Gadgetzan, Tanaris)
Master Gnomish Engineer = Oglethorpe Obnoticus (Booty Bay, Stranglethorn Vale)
Master Goblin Engineer = Nixx Sprocketspring (Gadgetzan, Tanaris)
Master Goblin Engineer = Vazario Linkgrease (Ratchet, The Barrens)

Master (to 375)
Mack Diver (Zabra'jin, Zangarmarsh)
Zebig (Thrallmar, Hellfire Peninsula)
Xyrol (Area 52, Netherstorm)

Alliance

Apprentice (to 75)
Bronk Guzzlegear (Kharanos, Dun Morogh)
Deek Fizzlebizz (Stonewrought Damn, Loch Modan)
Jemma Quikswitch (Tinker Town, Ironforge)
Sprite Jumpsprocket (Dwarven District, Stormwind City)
Jenna Lemkenilli (Auberdine, Darkshore)
Tinkerwiz (Ratchet, The Barrens)

Journeyman (to 150)
Finbus Geargrind (Darkshire, Duskwood)
Lilliam Sparkspindle (Dwarven District, Stormwind City)
Trixie Quikswitch (Tinker Town, Ironforge)

Expert (to 225)
Springspindle Fizzlegear (Tinker Town, Ironforge)

Artisan (to 300)
Buzzek Bracketswing (Gadgetzan, Tanaris)
Gnome Engineering Quest - Starts with Springspindle Fizzlegear (Tinker Town, Ironforge)
Goblin Engineering Quest - Starts with Nixx Sprocketspring (Gadgetzan, Tanaris)
Master Gnomish Engineer = Oglethorpe Obnoticus (Booty Bay, Stranglethorn Vale)
Master Goblin Engineer = Nixx Sprocketspring (Gadgetzan, Tanaris)
Master Goblin Engineer = Vazario Linkgrease (Ratchet, The Barrens)

Master (to 375)
Lebowski (Honor Hold, Hellfire Pen
Xyrol (Area 52, Netherstorm)
K. Lee Smallfry (Telredor, Zangarmarsh)