Here are some links we recommend:
 
Western Star Leather
I recently saw this guy at a show, and really liked his work.

A.G. Russell

Knife Forums

Blade Forums

Vintage Knives

"The Keen Edge of Perfection - A History of the Morseth Knife."  Written by Jim Beall with Gordon Morseth.

National Geographic News

Arizona Custom Knives

Steel Addiction Knives