For more information on Kerberos, refer to the following resources.
/usr/share/doc/krb5-server-<version-number> — The Kerberos V5 Installation Guide and the Kerberos V5 System Administrator's Guide in PostScript and HTML formats. You must have the krb5-server package installed.
/usr/share/doc/krb5-workstation-<version-number> — The Kerberos V5 UNIX User's Guide in PostScript and HTML formats. You must have the krb5-workstation package installed.
http://web.mit.edu/kerberos/www — Kerberos: The Network Authentication Protocol webpage from MIT.
http://www.nrl.navy.mil/CCS/people/kenh/kerberos-faq.html — The Kerberos Frequently Asked Questions (FAQ).
ftp://athena-dist.mit.edu/pub/kerberos/doc/usenix.PS — The PostScript version of Kerberos: An Authentication Service for Open Network Systems by Jennifer G. Steiner, Clifford Neuman, and Jeffrey I. Schiller. This document is the original paper describing Kerberos.
http://web.mit.edu/kerberos/www/dialogue.html — Designing an Authentication System: a Dialogue in Four Scenes originally by Bill Bryant in 1988, modified by Theodore Ts'o in 1997. This document is a conversation between two developers who are thinking through the creation of a Kerberos-style authentication system. The conversational style of the discussion make this a good starting place for people who are completely unfamiliar with Kerberos.
http://www.ornl.gov/~jar/HowToKerb.html — How to Kerberize your site is a good reference for kerberizing a network.
http://www.networkcomputing.com/netdesign/kerb1.html — Kerberos Network Design Manual is a thorough overview of the Kerberos system.