First, you'll need CUPS. If you have a Hewlett-Packard printer (HP brand), add the HPLIP package.
Then go to http://localhost:631 with your web browser and follow the steps to "Add Printer". It'll ask you to log in to add a printer. Log in as root, then finish the steps. Once you're done, you should be able to print.
If that doesn't work, you may also need to add HPLIP's dependencies separately. There currently is no package for CUPS DDK or foomatic.