There are a number of special-interest FAQ's on different subjects related to system administration and use, and also on miscellaneous topics like Flying Saucer Attacks (the music) and support for recovering sysadmins.
The official Usenet FAQ archives are: ftp://rtfm.mit.edu/pub/usenet/.
The Internet FAQ Consortium provides a searchable archive at: http://www.faqs.org/. The site also maintains a current archive of Internet Request For Comment (RFC), Best Current Practices (BCP), and For Your Information (FYI) documents.
Here are some FAQ's and documents that might be especially useful, and their network addresses: