HTML
<!doctype html>
<html>
<head>
<title>Page title</title>
</head>
<body>
<header><h1>Page title</h1></header>
<nav><!-- Navigation --></nav>
<section id="intro"><!-- Introduction --></section>
<section><!-- Main content area --></section>
<aside><!-- Sidebar --></aside>
<footer><!-- Footer --></footer>
</body>
</html>
Each section could have its own <header><nav> ...
<article> for blogs