While I wrote some of the login security for Unix System V and have been using Ubuntu on an old laptop for email and surfing for a few years, my Unix skills have atrophied and knowledge of Ubuntu is limited.
I want to move my 90+ year old mother to Ubuntu due to her limited computer use (email, skype, surfing, facebook) and would like to have a very obvious shutdown button. I'll be installing the latest Ubuntu release using all the defaults.