The only information I could find on being a courier was on the official website of the International Association of Air Travel Couriers. The site has information on being a courier. You can join the association there for $45 and receive a one year membership to the IAATC, one year of Travel Guide Magazine, The Shoestring Traveler courier newsletter, and a free copy of the IAATC Courier Handbook.
Susan - Thrifty Fun Editor
Three months ago I sent money for a one year's membership to Courier.org (a money order to their physical address) and I never heard from them. They did not answer my e-mails or phone calls.