There are 2 software way and 1 hardware way to print to a non-parallel printer:

Use the DEVS:NSDPatch.cgf to redirect output from the parallel.device to the lpr.device (which is how I access my 3 networked printers in my office) setting up the configuration file (ENV:) for each one and then an IconX script copies the information for the one I need with the click of an icon. You can use this method with the usbprinter.device. It will look like this:

DEVICE parallel.device UNIT 0 MAPTODEVICE lpr.device MAPTOUNIT 0
or
DEVICE parallel.device UNIT 0 MAPTODEVICE usbprinter.device MAPTOUNIT 0

You must run SetPatch on startup to use the NSDPatch.cfg file; check it in a cli> SetPatch
"AMIGA ROM Operating System and Libraries
Copyright (C) 1985-2011 Hyperion Entertainment VOF and others.
All Rights Reserved.

SetPatch (V53.1) has already been installed. Patch list:
None.
SetPatch is mapping parallel.device/0 to lpr.device/0"

The third way is a hardware shortcut using the LPT2USB device~ http://www.lpt2usb.net/ a $69 USD device based on a DIY German project (instructions are available on the web somewhere). This way you just print normally (you need a built in PAR: port which my X1000 lacks, but my A4000T has). Mine was for sale on AmiBay months back, but never sold.

For my network my Dell 5130cdn has the lpr.device file saying "HOST=192.168.0.117 RAW PORT=9100"
The following xxx.prefs file refer to the postscript settings:
printer.prefs, printergfx.prefs, printerps.prefs.
For my HP Inkjet, the IP number changfes as do the prefs files, and the IconX script copies the files into their correct ENV locations before I print.