nested div tags use for web design with greater posining

Some thing like this?

<div class="bodyclass">
<div class="header">
A Header for the page
<div class="navigation">
The Navigation bar stuff
</div>
</div>
</div>

Just set the css page items to your requirements.
Here is an example...

.bodyclass
{
    margin-left:auto;
    margin-right:auto;
    width:1024px;
    height:900px;
}
.header
{
    margin-left:auto;
    margin-right:auto;
    width:1024px;
    height:100px;
    background-color:rgb(41,110,43);
    padding-top:5px;
    font-size:72px;
    text-align:center;
    color:rgb(204,245,100)
}
.navigation
{
    background-color:rgb(204,245,100);
    width:1024px;
    height:27px;
    font-family:Andalus;
    font-size:medium;
    color:Maroon;
}

You're right - mastering DIV elements, combined with CSS, will make you a master of web pages, but to reach the next level you have to master Master Pages to really reach the peak of perfection.

Dave's answer provides some excellent examples of applying this technique to individual pages, but for a truly professional look, all pages on a site should have a similar look and feel, except where the functionality of specific pages precludes consistency. Master pages allow you to use your CSS and DIV skills to create one or more templates for layouts and style, then embed them in individual pages. Since a single site can have more than one Master Page, you can design one for text pages, one for tabular data pages, and another for media content, then combine them for really professional looking results.

Master pages save you the tedious work of remembering which style you used on previous pages as you develop the design and content. AThere's no need to keep track of all the various fonts and sizes you've used before, as including the Master Page takes care of that. All you really have to remember is what class you want to use for each section of the page.