Need Help with nav bar

[Noobkiller]

I want to add certain categories to my nav bar, but I don't know how and the nav lists all of my pages. I know it has to do with my category id, but I'm clueless through the rest.I'm changing my blog to use the Not So Fresh theme. Here's the code

PHP Code:

<div id="navbar">
        <ul class="menu">
            <li class="<?php if ( is_home() ) { ?>current_page_item<?php } else { ?>page_item<?php } ?>"><a href="<?php echo get_settings('home'); ?>"><?php _e('Home'); ?></a></li>
            <?php wp_list_pages('sort_column=id&depth=1&title_li='); ?>
            <?php wp_register('<li>','</li>'); ?>
        </ul>

[themelab]

This might help: Template Tags/wp list categories « WordPress Codex