Models
National Model Railroad Association (NMRA) - http://www.nmra.org/
An organization of model railroaders, advances the worldwide scale model railroading community through education and standards as well as advocacy and fellowship.
Scale R/C Models - http://www.scalercmodels.com/
A new company dedicated to the scale enthusiast for providing scale drawings, airplane kits, and accessories for kits from the early days of flight to the modern day of Jet aircraft.
Ztrains - http://www.ztrains.com/
Learn about the world of Z scale (1:220) model railroading.