[danik.js]

Это просто:

<div class="title">Title 1</div>
<div class="title">Title 2</div>
<div class="title">Title 3</div>

<div class="block">Block 1</div>
<div class="block">Block 2</div>
<div class="block">Block 3</div>

<script src="//code.jquery.com/jquery-latest.js"></script>
<script>
var $titles = $('.title');
var $blocks = $('.block');

$blocks.hide();

$titles.click(function(){
    var index = $(this).index();
    $blocks.eq(index).show();
});
</script>