Can you tell us what operating system you are using and how the printer is connected to your machine, Is it via USB cable?
Also what model is your Canon printer?
Could you Go to System Preferences/Print & Fax and you should see your printer listed there on the left side. Right click on it and select Reset Printing System to remove your printer from the machine.
Once you have done that could you restart your mac and then download the correct printer driver from the top of the list after choosing OSX from the OS list http://www.usa.canon.com/consumer/controller?act=ModelInfoAct&tabact=DownloadDetailTabAct&fcategoryid=334&modelid=15402
Once downloaded to the desktop can you then run the program and reinstall your printer.
Once installed try printing and let me know what happens.
Can you click the Apple logo and then select System Preferences which will open another window.
From there can you select printers and faxes and find your printer in the list, Then if your mac can print a test page it wil be listed, If not you will need ot open a document and try to print it as a test.
To right click hold down the CTRL key and click.