Give the element and id and point to it via the href attribute for the link like so

HTML Code:
<a href="#mySection">MySection</a>
using the first example is for a to top link where the link remains empty. This method works better with less tag usage. An example of this in practice is below. Save it was index.html and open it up. Click one of the links t be taken down to that section.

HTML Code:
<!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>Untitled Document</title>
<style type="text/css">
div#l { width:100%; height:600px; background: #CCC; }
div#m { width:100%; height:600px; background: #999; }
div#n { width:100%; height:600px; background: #666; }
</style>
</head>

<body>

	<div id="links">
		<a href="#l">L section</a>
    	        <a href="#m">M section</a>
    	        <a href="#n">N section</a>
	</div>

	<div id="l">SomeText</div>

	<div id="m">SomeText</div>

	<div id="n">SomeText</div>

</body>
</html>