In order to be sure that you are always referring to the latest version you should read the tutorial at its permanent home.
Nevertheless, there is the option to download the complete online tutorial.
When doing so, feel free to make it available locally at your site. Please do not publicly mirror it to the Web! If you were to do so, search engines may not find the original up-to-date version but list mirror sites instead. Those will fall behind inevitably, resulting in us receiving e-mails on topics which may be updated already.
Download the online tutorial