Prova così
codice:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>

<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Documento senza titolo</title>
<style type="text/css">
<!--
* {
	margin:0;
	padding:0;
}
body {
	font-family: Tahoma, Verdana, Arial, sans-serif;
	line-height: 1.3em;
	font-size: 11px;
	color: #666;
	background: #fff;
	text-align:center;
}
#contenitoreGenerale {
	width:100%;
}
#intestazione {
	width:100%;
	height: 250px;
	background: repeat-x url(images/page_bg.png) center top;
}
#logo {
	width:956px;
	height: 250px;
	background: no-repeat url(images/wrapper.png) center top;
	margin:0 auto;
}
#corpo {
	background: #eff4f7;
	width: 900px;
	margin:0 auto;
}
#menu{
	float: left;
	width:190px;
}

#testo{
	width:710px;
	margin-left:190px;
	background: #fff;
	text-align: left;
	color: #39f;
}	
* html #testo{ /* solo per explorer6 */
	width:707px;
}	
div#footer{clear:both} 

-->
</style>
</head>
<body>
<div id="contenitoreGenerale">
	<div id="intestazione">
	  <div id="logo">[img]images/headerimg.jpg[/img]</div>
	</div>
	<div id="corpo">
		<div id="menu">
		  

men</p>
		</div>
		<div id="testo">
		  

TESTO TES+</p>
		</div>
    </div>
  <div id="footer"></div>
</div>
</body>
</html>