I am trying to do the same thing but so far no luck.
I have an iPad that I installed HP's ePrint app on.
I have an HP 3015 Laserjet all in one printer hooked up to a PC running Windows 7 that I can access thru my network and print from the other Windows Computers on my LAN no problem.
But when I try and use HP's ePrint service, it seems to only find another printer that I have on my network (a Brother HL-2280DW wireless printer). It doesn't list the HP3015 as an option.. If I send the job to the Brother printer, it just prints jibberish or a solid black box.
Thanks in advance for any help you can provide.
tom