How do I create custom regions in a theme?
You define regions in your theme .info file. See: Structure of the .info file

You then need to put the relevant template tags in your page.tpl.php file. 

So for example if you defined the region sidebar in your themes .info file, you would then add: &lt;?php print render($page['sidebar']); ?&gt; to the relevant place in your page.tpl.php.