If you've already got lpd setup to print to your printer, or your system administrator already did so, or your vendor did so for you, then all you need to do is learn how to use the lpr command. The Printing Usage HOWTO covers this, and a few other queue manipulation commands you should probably know.
If, however, you have a new system or new printer, then you'll have to set up printing services one way or another before you can print. Read on!