Here is what I did:
1) Setup your printer using CUPS on the Debian Box, and print a test page.
2) Add a new printer on the Mac using CUPS. I set the "Device" to be "Internet Printing Protocol (http)". The Device URI should be http://hostname:631/printers/Printer.
Print another test page to make sure all is well.
Printer is the name of the print queue on my Debian Box - Replace it with the name of yours. Hostname can also be the IP address of your Debian Box.
I hope this helps