Rene Ritchie gives a nice guided tour of Siri setup. A perfect link to pass along to the less iOS-savvy of your friends and family.
But even if you’re an old hand, scan through the article. This is a current pass through all the settings, good for a refresher. Always a chance there’s something new that you’ve not used before.
Since Siri is usually activated by just holding down the Home button, it can pose a security risk to the data on your iPhone or iPad. If you are security conscious and have activated a Passcode Lock for your iPhone or iPad, you may want to make sure Siri isn’t allowed to bypass that lock — it’s less convenient, but that’s always the cost of security.
I didn’t know you could bring Siri under passcode protection. Cool.