I setup my Laptop with Gnome3 and was suprised that the printer was not automatically added, I know for sure that it was added automatically with earlier version... Guess that has nothing to do with gnome itself, sometimes there is some other kind of trouble. My Printer is a old multi-functional Canon (scan/print/fax) MP780 the scanning with simplescan (standard program from Gnome3) works pretty well. If you look for drivers in the Inet, there is just commercial software, like Turboprint. I tried it but had some issues after a while, and don't really want a kind os software suite just for printing... I looked further and noticed that there are free drivers called gutenprint, already available in Debian. Basically the steps you need to configure the printer were
apt-get install cups cups-driver-gutenprint