Emma Jane Hobgin (aka emmajane) gives an overview of her DrupalCon San Francisco presentation on PHP for Designers. She talks about the importance of pattern recognition and forensic coding, some helpful modules such as Devel Themer as well as some of the basics of Drupal theming with tpl.php files and preprocess functions within the template.php.

For more information, be sure to check out her PHP for Designers presentation.