How do I get my HP Officejet K80 printer to work

Check the HP site for a driver for your OS. http://h20000.www2.hp.com/bizsupport/TechSupport/DriverDownload.jsp?prodNameId=2 0497&lang=en&cc=us&prodTypeId=18972&prodSeriesId=30000&taskId=135

I don't see any drivers there for Apple computers but I did not do an extensive search.

If there are no drivers then you are out of luck, unless you can find a generic driver that will work.

HP has no OS X drivers for that printer.

Try the Gutenprint driver: gutenprint-5.2.8-pre1.dmg

It allegedly supports the HP OfficeJet K80: Supported_Printers