Have I got a tip for you!
Three of them, actually!
First, read the post on this forum titled "Trade Skills Sticky". It's the first post on the forum, at the top.
Second, the menu on the left hand side of this website has a link called "List of Trainers..." right under the title "Tradeskills". Check it out.
Third, in game, if you speak to a tradeskill trainer, they will mention who to see to further your skills.
Edited, Sep 6th 2006 at 11:15am EDT by thermalnoise