This is from the view source of your main page:
Code:
<div id="headerwrap" class="clearfix">
<div id="logo">
<div id="logoName"><img src="includes/templates/zcSohoSailing/images/logo.gif" alt="" /></div>
</div>
<!-- End Header Wrapper --></div>
I'm guessing the portion in red is what you want to change.
The question is do you want to change includes -> templates -> YOUR_TEMPLATE -> common -> tpl_header.php (which as it appears is where you have it now) or do you want to include it in your stylesheet.css?
If you want to change it in tpl_header.php find this line:
<img src="includes/templates/zcSohoSailing/images/logo.gif" alt="" /> and just change gif to png.
if you want to include the img reference in your stylesheet find this:
Code:
div#logoName {
float: left;
height: 50px;
width: 300px;
}
and change it to
Code:
div#logoName {
float: left;
height: 50px;
width: 300px;
background: url(../images/logo.png) no-repeat;
}
remove the line above from tpl_header.php