Greenhouse Fabrics: Great fabrics at reasonable prices
Build.com: Source for plumbing, lighting, accessories and more
DL Couch: Commercial and residential wallcoverings
Thibaut: Residential wallcoverings in a more traditional style
Sherwin Williams: Paint, including a great preview tool!
Benjamin Moore: Paint, including a great preview tool!
Hunter Douglas: Window treatments - the best and most innovative in the industry
Graber: Window treatments - great quality and an affordable price
ASID: The American Society of Interior Designers
Art.com: Online source for Art and Frames