Here are some useful things you can do using functions:
Add a function to your ~/.bashrc config file that automates the printing of man pages. The result should be that you type something like printman <command>, upon which the first appropriate man page rolls out of your printer. Check using a pseudo printer device for testing purposes.
As an extra, build in a possibility for the user to supply the section number of the man page he or she wants to print.
Create a subdirectory in your home directory in which you can store function definitions. Put a couple of functions in that directory. Useful functions might be, amongs others, that you have the same commands as on DOS or a commercial UNIX when working with Linux, or vice versa. These functions should then be imported in your shell environment when ~/.bashrc is read.