The best source of information is the US Department of
Transportation. All carriers must file their fares with them for
tariff purposes.

   A variety of companies publish rate guides based on the US
Department of Transportation files. The subscription prices are a bit
steep, but your library may have some.

The Travelers' Tales Travel Resource Center provides travelers with
current information on international news, weather, discounted air
tickets, access to Internet travel newsgroups, currency rates and
where and how to use credit cards, and much more. The Travel Resource
Center was created by O'Reilly & Associates as an informational
companion to their Travelers' Tales books.  The Travel Resource Center
is a free service, and can be accessed through the Global Network
Navigators' Marketplace section. (To view GNN or the Travel Resource
Center you must be able to support the WWW [World Wide Web] browser.
The URL for the TRC is http://gnn.com/gnn/meta/travel/index.html)
To obtain a free subscription to GNN, send an email message to:
info@gnn.com. Additional information about this free service can be
obtained by writing to Allen Noren <allen@ora.com>.

The rec.travel Library is available by anonymous ftp from
   ftp.cc.umanitoba.ca:/rec-travel.
A WWW server for the library is
   ftp://ftp.cc.umanitoba.ca/rec-travel/README.html

Some parts © 2009 Advameg, Inc.