FTPLab.Com
How to choose an FTP program. About tasks which can be performed by a special program called FTP Clients.

FTP Protocol Overview
Very brief (1 page) overview of FTP. Part of "Connected: An Internet Encyclopedia"

FTP File Transfer Protocol
Lecture slides providing an overview of FTP by "Dave H".

The Internet and FTP
One of the most useful services of the Internet is FTP, or File Transfer Protocol. This paper describes the client/server environment and explains FTP conventions and issues.

FTPmail: FTP by email
FAQ describing how to download from ftp sites with email.

FTP: File Transfer Protocol
Reference manual aiming to describe how FTP actually works (and doesn't work) in practice.