I use this app to print from my iPad to an ancient (but reliable) HP Laserjet 6MP that I have connected to my LAN using an external printserver. The printserver device essentially turns the HPLJ6 into a standalone networked printer.
The trick was finding an iOS printing app that spoke the same protocol as the printserver device, in my case, Unix-style LPR/LPD printing.
[Since I can't post URLs yet, you'll just have to search the AppStore for 'ePrint' if interested in this app]
I recall there was another app (I think it was Print Magic) that also offered the ability to talk directly to a network printer w/o requiring a separate Mac/PC. At the time, I couldn't quite get it working properly with my setup. However, I believe there is a free version of the Print Magic that gives you a chance to test your printer/printserver compatibility before buying the full app.
Reminder: Most, if not all 3rd party printing apps WON'T work directly with the default 'Print' button found in most apps that support printing (e.g. Pages and Numbers) -- these expect to use the AirPrint service. Instead, you'll have to open/export the document you want to print into the 3rd party app and print from there. Of course, if you're reading this thread, you're probably well aware of this fact.
