Q: How to use Siri on iPhone 5

Hold down the Home button until you hear the tone and see the microphone on the bottom of the screen. Then ask your question.

I have Siri set reminders for me just by asking. Saves typing. I also am constantly asking about football scores and other stuff. Mostly Siri does fairly well but there are some things that just don't come out right. If that happens don't worry, nothing lost, try asking again in a different way. Sometimes that helps.

Try this support document http://support.apple.com/kb/HT4992. It is different from the one you linked here from.