STUDY GROUPS/CLUBS

American Philatelic Society: All serious collectors should consider joining this organization.
Hawaiian Post Study: Comprehensive source of information on 19^th century Hawaiian stamps and postal history.
United States Stamp Society (formerly the Bureau Issues Association): promotes the study of philatelic output of the Bureau of Engraving and Printing (and other printers). Durland Standard Plate Number Catalog available.
US Philatelic Classics Society: An interesting study group.
Virtual Stamp Club: An interesting stop with articles and useful links.

TOPICAL COLLECTING

American Topical Association: Help for collectors of topicals or thematic collections.
Federal Duck Stamps

British Postal Service: Great Britain stamp and postal information
Canada Post
Sweden Post Stamps
United Nations Postal Administration
USPS: For a look at up-coming stamp releases, looking up Zip+4 codes, or just checking the current postage rates.

e-BUSINESS

	You can find a great selection of philatelic reference catalogs at Amazon.com.
Universal Currency Converter	Helps you convert from one currency to another.
	eBay - The biggest online source for stamps! Whether you're buying or selling, this is the place to start!
	The #1 Online payment method.