Q5.3.12: What do I need to change to make printing work?

For regular printing there are two variables that can be customized.

lpr-command

This should be set to a command that takes standard input and sends it to a printer. Something like:

(setq lpr-command "lp")

lpr-switches

This should be set to a list that contains whatever the print command requires to do its job. Something like:

(setq lpr-switches '("-depson"))

For postscript printing there are three analogous variables to customize.

ps-lpr-command

This should be set to a command that takes postscript on standard input and directs it to a postscript printer.

ps-lpr-switches

This should be set to a list of switches required for ps-lpr-command to do its job.

ps-print-color-p

This boolean variable should be set t if printing will be done in color, otherwise it should be set to nil.

NOTE: It is an undocumented limitation in SXEmacs that postscript printing (the Pretty Print Buffer menu item) requires a window system environment. It cannot be used outside of X11.