CSS Image Hover

I’d like to implement a rollover image over one of my page links. Here’s my code:

<ul>
<li class="page_item page-item-212"><a href="https://localhost:8888/wordpress" title="home">home</a></li>
<li class="page_item page-item-6"><a href="https://localhost:8888/wordpress/test123/" title="about">about</a></li>

<li class="page_item page-item-52"><a href="https://localhost:8888/wordpress/contact/" title="contact">contact</a></li>
</ul>

Any good tutorials out there that can show me the way?