SO http://is.gd/xUQCTs

HTML

<link rel="stylesheet" href="http://netdna.bootstrapcdn.com/twitter-bootstrap/2.3.0/css/bootstrap-combined.min.css">
<script src="http://netdna.bootstrapcdn.com/twitter-bootstrap/2.3.0/js/bootstrap.min.js"></script>
<div class="container">
  <div class="row">
    <div id="side-nav" class="span3">
      <ul class="nav nav-list affix">
        <li><a href="#one">One</a></li>
        <li><a href="#two">Two</a></li>
        <li><a href="#three">Three</a></li>
        <li><a href="#four">Four</a></li>
        <li><a href="#five">Five</a></li>
      </ul>
    </div>
    <div class="span9 content">
      <section id="one">
           Section 1
      </section>
      <section id="two">
           Section 2
      </section>
      <section id="three">
           Section 3
      </section>
      <section id="four">
         Section 4
      </section>
      <section id="five">
        Section 5
      </section>
    </div>
  </div>
</div>

CSS

.content section {

  margin-bottom:20px;
    height:750px;
}