Is this home page well organized and what can I do to improve performance here?
your structure looks good.

I am sure you have a reason for nesting so many &lt;div&gt;s 

you know that you  can add classes to Tags as well, and you don't have to add them to only &lt;div&gt; tags you can add them to other tags.

it just looks like you are surrounding some tags with Div tags because you think you can only style them that way.

like this

&lt;div id="headerTagline"&gt;
  &lt;h1&gt;CAD/CAM Digital Dental Restorations&lt;/h1&gt;
&lt;/div&gt;


you can change to this

&lt;h1 id="headerTagline"&gt; CAD/CAM Digital Dental Restorations &lt;/h1&gt;


or

&lt;h1 class="headerTagline"&gt;CAD/CAM Digital Dental Restorations&lt;/h1&gt;