IMac (Intel) :: Can't Connect HP Photosmart C7280 Wirelessly

Yesterday I purchased my first ever iMac (OS X 10.9.4 - Mavericks I believe). 

I'm trying to connect my HP Photosmart C7280 printer to work wirelessly but can't seem to work out how to do it. 

When I connect via a USB the printer is recognised in Printers & Scanners, when I remove the USB the printer disappears. 

My Mac and printer are both connected to the same wireless network (which we get through Virgin Media) - although my printer displays "no link" for IP address, don't know if this is relevant. 

I have tried resetting print system, I have downloaded all Apple system updates, I have downloaded the latest driver I could find from the HP site (although this might have been unnecessary). 

One factor that may be significant is that when I view the printer details (when connected via USB) I see the Mac's name, the printer model and the status but I don't see any reference to a Driver, which from what I've read, I feel I should be seeing.

I've also read reference to clicking "use" in a drop-down menu but from the details I see in the printer pane/dialogue box? I cannot see "use" anywhere or any other drop-down menus. 

by the way, the printer always worked perfectly well wirelessly when connected to a Windows laptop on the same network, 

Info:
iMac, OS X Mavericks (10.9.4)