The Internet provides a wealth of resources, covering all aspects of the hobby.
These resources include:
American Philatelic Society
United States Postal Service
Linn’s Stamp News & Scott Publishing Co.
The Virtual Stamp Club
National Postal Museum (Smithsonian)
Arago: People, Postage & the Post
American Topical Association
American First Day Cover Society
The American Stamp Dealers Assoc.
Florida Stamp Dealers Assoc.
Collecting the World