How do I create custom regions in a theme? I want to add a new area which will be site wide. Describe the process of getting this new region into my theme, if possible generalize it for adding any new, custom region.
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.