Go to System Preferences and select Printers & Scanners
If this doesn't seem to be the issue, you can also reset your printing system. This will remove all of the printers in your list, so ONLY do this if you don't have any printers installed from home. (You can remove each printer by selecting the printer and clicking the "-" at the bottom of the list.)
Resetting the printer list needs to happen within our building, since the printers are on our network. To do this, hold down "CONTROL" and click on the printer list. Select "Reset printing system."
You must then restart your computer, allowing it to sync both on log-out and on log-in.
If you go back to your Systems Preference, you should now see a freshly repopulated list of printers.