My perspective is somewhat restricted, you know, knifenut on a budget.
Local dealers:
All local dealers I have found through either word of mouth or just happened to drive by and spotted them. The word of mouth for a couple of local dealers came through BladeForums community forum.
Internet dealers:
Before BladeForums I used search engines a lot and still do sometimes. More often I use either the BladeForums links or special offerings by dealers posted on BladeForums. Any dealer who does a knife giveaway automatically gets my attention. If the dealers doing the giveaways get positive comments on the Good, Bad & Ugly, they stay near the top of my list.
I use Bookmarks for my favorite dealers. I have too many bookmarks to list here
I haven't got the budget for custom knives yet, but by the time I do (after kids college expenses) I will know who to go to because of BladeForums.
My other internet sources are rec.knives and knifeforums. I monitor both of them regularly.
Knife & Gun shows:
I find these invaluable in finding and handling knives. The crowds are a bit of a hassle, but the hands-on time and meeting some of the dealers in person is worth a little hassle.
Before I buy any over $100 regular carry knife, I have to handle it. This restricts my higher dollar purchases to local purchase, gun & knife shows or internet dealers who will take back a knife you are not satisfied with out of the box. Any dealer who won't take back a knife doesn't get my business.
[This message has been edited by Bob Irons (edited 16 October 1999).]