The U.S. government offers many of its publications on the web. The Computer Security Resource Center (CSRC) of the National Institute of Standards and Technology (NIST) publishes articles on computer security. The following are a sample of the publications that can be downloaded from the NIST site.
An Introduction to Computer Security: The NIST Handbook. SP 800-12, October 1995.
Standard Security Label for Information Transfer. FIPS-188, September 1994.
Swanson, Marianne and Barbara Guttman. Generally Accepted Principles and Practices for Securing Information Technology Systems. SP 800-14, September 1996.
Tracy, Miles, Wayne Jensen, and Scott Bisker. Guidelines on Electronic Mail Security. SP 800-45, September 2002. Section E.7 concerns securely configuring LDAP for mail.
Wilson, Mark and Joan Hash. Building an Information Technology Security Awareness and Training Program. SP 800-61, January 2004. Includes a useful glossary.
Grace, Tim, Karen Kent, and Brian Kim. Computer Security Incident Handling Guidelines. SP 800-50, September 2002. Section E.7 concerns securely configuring LDAP for mail.
Scarfone, Karen,Wayne Jansen, and Miles Tracy. Guide to General Server Security SP 800-123, July 2008.
Souppaya, Murugiah, John Wack, and Karen Kent. Security Configuration Checklists Program for IT Products. SP 800-70, May 2005.