If you are using Jaguar, you simply have to download the BJC-3000.dmg file and lauch the installer.

You can also  download my entire Canon folder Canon.tgz.
Untar and UnGzip the file, then log as root and replace your Canon folder in /Libray/Printers.
Reboot you're Mac and here we go !

If you are using Mac OS X.1.x
You must create a BJC3000.icns in the BJPrinters/Ressources/icons folder 
and replace BJPrinterUtility file in Frameworks/BJPrinterUtility.framework
Then you should unstuff and place the PMs in your Canon PMs folder.
You should log as root to do this.
To log as root, the root access must be activated. You can activate root account with NetInfo Manager.