Just having the printer-driver installed may not be enough.
Do you have CUPS installed and running? (CUPS = Common Unix Printing System)
Also, did you add the printer via the "Add printer" option in your desktop environments settings manager?
The exact location of the "Add printer" option varies from DE to DE. Each DE has its own settings manager - But it's usually fairly easy to find.
That will ask you a few simple questions about the make/model of printer and will ask you to give it a name etc. and the printer will be set up in CUPS. You should also be given the option to set it as the systems default printer.
Once that's done, you should be able to print documents from any print-enabled program.
NOTE: If the new printer is NOT set up as the systems default printer. - Each time you want to print something you will need to open up the programs print settings and specify the correct printer to use - otherwise it will be sent to the default printer.
So if the new printer is always going to be used, don't forget to set it as the systems default printer.
On a system without a printer set up, it will use Document Writer (or some-equivalent) as the default printer. Which will mean that anything that is printed will be sent to a .pdf file somewhere.
If memory serves, I think you can also add a printer by visiting the local CUPS servers web-interface with your browser.
The local CUPS server web interface runs on port 631 on your PCs local loopback interface:
If you have CUPS running on your PC, opening that address in your browser should bring up its web interface and should give you the ability to add/remove printers and will also allow you to view/monitor any print-jobs. You may have to explore a little to find the admin options.
It's been a while since I've had to deal with adding a new printer, so I'm sorry if I'm a little vague with some of the details.
Either way - I'd say you need to either add the printer using your desktop environments "Add printer" settings, or take a look at CUPS web-interface and add the printer from there.