Printing to a Sharp AR-M450 using CUPS (the standard print system for most free *NIX and even Mac OS X) is possible, but took me some time to find the right settings. First, you need the printers IP address, in my case 10.2.0.98.
In CUPS you chose “Network Printer” and “lpd/lpr”. Then you set address=”10.2.0.98″ (replace with your own) and queue=”lpr”.
As printer driver, I chose “Generic PCL 6/PCL XL Printer”, using “CUPS+Gutenberg vX.X.X Simplified”.
This should get you running!