If by "artisan" you mean 225+ training, the guy is in Theramore in one of the buildings. He's labled as "Trauma Sergeon" or something like that. Its a quest you have to complete which currently requires level 40 (after patch 1.8 I believe it will require level 35).
Also, if you're capped at 225, making heavy silk bandages isn't going to net you many skill ups, as its a green recipe for me. The next step is mageweave bandages, which is learned through a book purchasable at Stormgarde Keep in Arathi Highlands (same place you get the book to learn 150+ first aid).
If you're referring to 150+ first aid training, go to Arathi Highlands (the next zone north of the Wetlands - level 30-40 zone, so stay on the road and be careful) and follow the road north, then west at the split. Get the flight path in Refuge Pointe if you haven't already. Continue heading west until you see a castle structure off to the left of the road. Go into the main entrance and be careful. Stick to the right wall (there are level 35-ish elites on the left). Take your first right inside the fort and follow that road strait back until you start seeing friendly NPCs.
Back in that area you're safe. Follow the road back into that area and around to the right. Back in the garden/cemetary area there should be a vendor that sells a book that will teach you 150+ first aid.
Edited, Tue Oct 11 07:26:06 2005 by Chadness