I have a MacBook Pro that's about 3 years old and works fine. The Photosmart Premium C309G is about 2 months old and has been working fine. All of a sudden, last night, it would not print. I sent a document to the printer, selected the C309G, and the printer queue said that the object was printing but the printer did nothing. I reinstalled the printer, but got the same results with different documents. I do know that two cartridges are low. Would that have something to do with it or is it a deeper problem? If so, what should I do to get it working?

try from a different printer if you can.

Next shut down the mac and the printer.. unplug the printer n wait about a min.
make sure you unplug it from the wall and the mac. (usb)
next plug the printer in.. then plug its usb in to the mac.. then power it on
after power on the mac. sometimes things just need to be reset.

This could indeed be your cartridge is trying to print but doesnt have the ink to do so.. so
it does nothing