If you already have a html file from your design, and are using stock drupal, then the info on these pages (Convert any website layout or template into a Drupal theme - easily! and Assigning content to regions) of the theming guide will get you along.
In short, there are the following regions;
Just a maintenance project for this website.
I need something to track and plan **much needed** changes.
Some developers tend to make their own website the most beautiful, I tend to spend most of my time on "billable hours", so I need to do this like a project, otherwise it will be the same three years from now.
In any event it is also a nice showcase for a basic intra-net setup and the aggregation of messages from sub-systems.