CSS:とりあえずこんなのを追加

*{margin:0;padding:0;}

div,h2,h3,h4,h5{
border:solid 1px #003;
margin:5px;
padding:5px;
}

h1 {padding:50px;}

div.main{
	margin-left: 230px;
}

div.sidebar {
	position: absolute;
	top: 278px;
	left: 20px;
	width: 200px;
}