If you're using an up-to-date version of Ubuntu, and haven't told things not to update themselves, the answer is pretty nice:

You're doing it already.

Just hit the buttons that it tells you to hit when it tells you to hit them, and you'll always be up to date for ever and ever.

However, if you'd like to manually update your system, you can do this:

• run update-manager fairly frequently (read: weekly at the least).



• For those of you who like the command line, the following will update your system.

  
  
  

  sudo apt-get update && sudo apt-get dist-upgrade
  
  

  
  
  

  that command will update the repositories (the software list) and then install the latest updates.