Check if something like this is what you are looking for. You can then make your links in left.htm and have them change the pages in the frame named mainFrame.
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Frameset//EN" "http://www.w3.org/TR/html4/frameset.dtd">
<html>
<head>
<title>Frameset Demo</title>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
</head>
<frameset cols="80,*" frameborder="NO" border="0" framespacing="0">
<frame src="left.htm" name="leftFrame" scrolling="NO" noresize>
<frame src="right.htm" name="mainFrame">
</frameset>
<noframes>
<body>
</body>
</noframes>
</html>
