To install CUPS on your Ubuntu computer, simply use sudo with the the apt-get command and give the packages to install as the first parameter. A complete CUPS install has many package dependencies, but they may all be specified on the same command line. Enter the following at a terminal prompt to install CUPS:
sudo apt-get install cupsys cupsys-client
Upon authenticating with your user password, the packages should be downloaded and installed without error. Upon the conclusion of installation, the CUPS server will be started automatically. For troubleshooting purposes, you can access CUPS server errors via the error log file at: /var/log/cups/error_log. If the error log does not show enough information to troubleshoot any problems you encounter, the verbosity of the CUPS log can be increased by changing the LogLevel directive in the configuration file (discussed below) to "debug" or even "debug2", which logs everything, from the default of "info". If you make this change, remember to change it back once you've solved your problem, to prevent the log file from becoming overly large.