Here are some forums that I frequent, as well as some knife supply companies.

Usual Suspects

British Blades

Knife Network

Alpha Knife Making Supply

Sheffields Knifemaking Supply

Hawkins Knife Making Supplies

Crucible Steel

Halpern Titanium

USA Knife Makers Supply

Jerzee Devil Forums

Here are some sites that I like to check out, great makers the lot of them!

Kirby Lambert

Chris Daigle