set your page up like the below example, you can include a file at each div, so for menu make a file menu.php and in the menu div is just put
PHP:
<?php include 'menu.php'; ?>
and same with header and footer so each page only have to edit the stuff in right div and update your menu to include each page(assuming your right div is your body)
if you know php the cleanest way to do it is to have a index page
then include, a header, a footer and menu, and use a get variable to load the body content, and if your really clever clean it up with .htaccess mod-rewrite, thats more or less how cms is made statically, if you want it to be dynamic you just create your pages in a datebase with feilds for your meta data and title etc, and then you can use a while() loop in your menu to dynamically create the menu, but thats starting to get more complex now
HTML:
<style>
<!-- set your div styles -->
#header{
position:absolute;
width:200px;
hieght:whateva;
margin:wateva;
}
etc etc
</style>
<body>
<div id="page">
<div id="header">
header stuff here
</div>
<div id="left">
left stuff here( most likely menu)
</div>
<div id="right">
right (i assume body stuff here)
</div>
<div id="footer">
Footer stuff here
</div>
</div> <!-- close the page div -->
</body> <!-- close body div -->