These are some of the more useful sites on the Web for collectors and researchers, in no particular order.

http://atcaonline.com/phone/

Australasian Telephone Collectors Society

http://antiquetelephonehistory.com/

Chuck Eby's Telephone History Website of the American Telephone Collectors Association. Good history articles, many details of collections and phones worldwide.

http://www.antiquetelephones.net/

Neil Carpenter's collection of (mostly British) bakelite phones, as well as much other material of interest. Beautiful photos of rarities.

http://www.britishtelephones.com/

Bob Freshwater's comprehensive site covering British phones, British Ericsson, and many other companies. If you are looking for a British or British-produced phone, start here.

http://home.swipnet.se/~w-38835/indexeng.htm

Ove Svensson's telephone Pages. Covers Scandinavian phones, including Ericsson, in some detail. Includes photos of many rare phones.Information on Ericsson serial numbers, handsets.

http://www.mirz.homepage.t-online.de/

A website by Peter Mirz which lists just about every possible variety of the Ericsson skeletal phone, including skeletal lookalikes produced by other companies. The site is also available as a downloadable .pdf Acrobat file

http://www.telephonearchive.com/kelloggtelephone/index.html
Mike Neale's Kellogg website. Mike has collected brochures, history, catalogs and much more and made it available for download from his site.