WordPress theme step by step tutorial - Part 21: We almost finish our theme. But this not yet complete if us not yet talked about widget. Widget make our sidebar more dynamic. We can add and remove plugin more easy than always write code manually.
Open your "sidebar.php". Add following color code:

<div id="right_part">
<div class="sidebar_container">
<ul>
<? if ( !function_exists ('dynamic_sidebar') || !dynamic_sidebar()) : ?>
<li><h2>Pages</h2></li>
<? wp_list_pages('title_li=') ?>
</ul>
</div>
<div class="sidebar_container">
<ul>
<li><h2>Categories</h2></li>
<? wp_list_cats() ?>
</ul>
</div>
<div class="sidebar_container">
<ul>
<li><h2>Archives</h2></li>
<? wp_get_archives() ?>
</ul>
</div>
<div class="sidebar_container">
<ul>
<li><h2>Links</h2></li>
<? wp_get_links() ?>
<? endif; ?>
</ul>
</div>
</div>
Then, create a file named "functions.php". Add following code:
<?
if ( function_exists('register_sidebars') )
register_sidebars(1);
?>
Ok, now, login as administrator. And follow this instructions:

The result may look like this:
