[resolved] Adding login and register links to the header

Your first instinct was right. The two template tags you need are <?php wp_register(); ?> and <?php wp_loginout(); ?>. It's the placement within your header that's the problem. The header image is masking/hiding the links. Try adding:

<ul class="headerlinks">
<li><?php wp_register(); ?></li>
<li><?php wp_loginout(); ?></li>
</ul>

immediately after <div id="header"> in header.php.

Then add the following to style.css:

#header .headerlinks {
 position:relative;
 top:20px;
 left:600px;
 z-index:500;
}
#header .headerlinks {
 display:inline;
 margin:0 5px 0 0;
 padding:0;
}