Have a look at the following document which validates as HTML5
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Untitled Document</title>
<style>
body {width: 980px; margin: auto;}
#content {width:100%; float:left; margin-right:-200px;}
#sidebar {width:200px; float:left;}
ul {list-style:none;}
li {line-height:1.3em;}
.col2 {margin-left:100px;}
.col3 {margin-left:200px;}
.top {margin-top:-2.6em;} /* the clincher */
</style>
</head>
<body>
<div id="content">
<h1>Main content in here</h1>
<ul>
<li class="col1">Eggs</li>
<li class="col1">Ham<li>
<li class="col2 top">Bread<li>
<li class="col2">Butter<li>
<li class="col3 top">Flour<li>
<li class="col3">Cream</li>
</ul>
</div>
<div id="sidebar"> <p>I’m the Sidebar! </p> </div>
</body>
</html>
Gramps
