Raw Materials & parts:
US Plastic Corporation - great prices on UHMW & Delrin
Equipment Vendors:
Little Machine Shop - One of the best
Lathe Master - Just bought the 9X30 lathe, great machine. Now Offline
Shars Tool Company - Great prices
Forums:
Practical Machinist - Includes a gunsmith forum
Home Machinists Round Table Yahoo Group - Mostly off topic now but has good resources
Mini Lathe Modifications Yahoo Group
The Mini Mill Discussion Yahoo Group
Miniature Tools & Tool Making Yahoo Group
My Little Machine Shop Yahoo Group
ShumaTech Yahoo Group - DIY DRO
Please note: You may need a Yahoo Groups login just to get to the forums I've listed under Yahoo groups. In other words, you may get a nag screen before it will let you into any of them if it doesn't recognize you as a member or something like that.
General Interest:
Here are links to sites with more lists of metal working site links:
Articles About the Taig, Tips, and Accessory Drawings
Pat's Big List Of Metalwork Links
Mini lathe or Mini mill needs.
Mini Lathe - Good site for the mini lathe.