You may find the following books useful as Apache references:
Coar, Ken, and Rich Bowen. Apache Cookbook. Newton, MA: O’Reilly Media, Inc., 2003.
Laurie, Ben, and Peter Laurie. Apache: The Definitive Guide. 3rd ed. Newton, MA: O’Reilly Media, Inc., 2002.
Wainwright, Peter. Pro Apache. 3rd ed. Berkeley, CA: Apress, 2004.
A CGI reference is
Hamilton, Jacqueline D. CGI Programming 101: Programming Perl for the World Wide Web. 2nd ed. Houston, TX: CGI101.com, 2004.
A more in-depth treatment of the LAMP framework can be found in the following:
Glass, Michael K., Yann Le Scouarnec, Elizabeth Naramore, Gary Mailer, Jeremy Stolz, and Jason Gerner. Beginning PHP, Apache, MySQL Web Development. Hoboken, NJ: Wrox, 2004.
Rosebrock, Eric, and Eric Filson. Setting Up LAMP: Getting Linux, Apache, MySQL, and PHP Working Together. Berkeley, CA: Sybex, 2004.
The Apache web site at http://httpd.apache.org/ contains much up-to-date Apache documentation. O’Reilly Media, Inc.’s http://www.onlamp.com/ is a well-maintained source of current information and tutorials on LAMP.