The following bit of code is producing the nthellworld Nav bar
Code:
<a href="usercp.php?"><img src="images/buttons/top_profile.gif" alt="top_profile.gif" title="Here you can view your subscribed threads, work with private messages and edit your profile and preferences" border="0" vspace="8" /></a>
<a href="calendar.php?"><img src="images/buttons/top_calendar.gif" alt="top_calendar.gif" title="Calendar" border="0" vspace="8" /></a>
<a href="memberlist.php?"><img src="images/buttons/top_members.gif" alt="top_members.gif" title="Find other members" border="0" vspace="8" /></a>
<a href="faq.php?"><img src="images/buttons/top_faq.gif" alt="top_faq.gif" title="Frequently Asked Questions" border="0" vspace="8" /></a>
<a href="search.php?"><img src="images/buttons/top_search.gif" alt="top_search.gif" title="Search" border="0" vspace="8" /></a>
<a href="index.php?"><img src="images/buttons/top_home.gif" alt="top_home.gif" title="Home" border="0" vspace="8" /></a>
Basically you create a hyperlink with <a> and then use an image inside the hyperlink.