DrupalThemesOnly

Okay the basic layout of your site is controlled by the page.tpl.php file. Its basically html with some php type includes that hold variables like your regions.

This page is your main layout and is a great starting point for you. Drupal.org has an example file or just take one of your existing themes and take a look. You can edit it as you like.

The video shows the basics for creating a page.tpl.php file and shows how the variables, especially the regions are pulled into the layout of your site. Again the video is by tom rogers, http://www.tom-rogers.com