i want desin my homepage as follows..

My suggestion would be to design the page in a tabular layout(using tables or CSS absolute positioning) and use master page for the fixed part of the page. the variable part of the page can be put in the content pages. Refer this article to know how it can be done:

Beginner's Tutorial on Master Pages in ASP.NET[^]

If you were to design the site using CSS, as you want to divide the page up in three sections you can use ID's.

E.g:

#leftpart
{
 // Design code here
}
#rightpart
{
 // Design code here
}
#content
{
 // Design code here
}

Then in HTML use the 'id' attribute in a div.

<div id="leftpart"></div>

I'm not best at CSS, but I believe you can find something more helpful on Google, or YouTube.
So, best of luck.