lpr(1) man page — Information on printing selected files on the printer of your choice.

lprm(1) man page — Information on removing print jobs from a printer queue.

cupsd(8) man page — The CUPS printer daemon.

cupsd.conf(5) man page — The file format for the CUPS printer daemon configuration file.

classes.conf(5) man page — The file format for the CUPS class configuration file.

Files in /usr/share/doc/cups-<version> — The document collection for CUPS.

http://www.webopedia.com/TERM/p/printer.html — General definitions of printers and descriptions of printer types.

http://www.linuxprinting.org/ — A database of documents about printing, along with a database of nearly 1000 printers compatible with Linux printing facilities.

http://www.cups.org/ — Documentation, FAQs, and newsgroups about CUPS.

Network Printing by Matthew Gast and Todd Radermacher; O'Reilly & Associates, Inc. — Comprehensive information on using Linux as a print server in heterogeneous environments.

The Red Hat Enterprise Linux System Administration Guide; Red Hat, Inc. — Includes a chapter on printer configuration.