This video walks through the process of replacing static content in the page.tpl.php file with dynamic variables. Joe talks about the html.tpl.php file as well as pointing some of the important variables that should be included within the theme.
Check your version
This video covers a topic in Drupal 7 which may or may not be the version you're using. We're keeping this tutorial online as a courtesy to users of Drupal 7, but we consider it archived.