Mentor Graphics - The EDA Technology Leader
Downstream Technologies - Helping Engineering Organizations to Streamline the PCB release process
IPC Designers Council - Promote  the exchange of information and integration of new design concepts
IPC - Association Connecting Electronics Industries
SMTA - The Surface Mount Technology Association
Online Coversion - Convert just about anything to anything else
PCB0007 Magazine - Online PCB Magazine
Advanced Circuits -  Prototype and Production Bare PCB