To accompany the release of iOS 7, Apple has made the official user guides for iPhone, iPad and iPod touch available to download for free from iBooks. Many of us will just dive right in with both feet, but it's nice to know that there's a full compendium of information at our disposal should we find ourselves caught short with something.
An iPhone specific guide isn't there yet, but the iPod touch guide should at least cover a lot of it. Grab it from the links below for the device of your choice. iOS 7 isn't quite with us yet, but maybe these will help pass the time.