<div>
<h1>Main title</h1>
<h2>Section title</h2>
<p>Some content...</p>
<h2>Section title</h2>
<p>More content...</p>
</div>

$('h1 + h2')
// Select ALL h2 elements that are adjacent siblings of H1 elements.

$('h1').siblings('h2,h3,p');
// Select all H2, H3, and P elements that are siblings of H1 elements.

<ul>
<li>First item</li>
<li class="selected">Second Item</li>
<li>Third item</li>
<li>Fourth item</li>
<li>Fifth item</li>
</ul>

$('li.selected').nextAll('li');

$('li.selected ~ li');

var topHeaders = $('h1');
topHeaders.next('h2').css('margin', '0);