How do I list all Entries with a certain tag in Wordpress?

If you are comfortable with hacking WP you can try adding to your sidebar with wp_list_pages.

Or there are plug-ins like Simple-Tags that help you manage your tags.

The nice thing about WordPress is there are lots of plug-ins available that can add functionality that the base app does not ahve, a quick search for plug-ins for tabs returned quite a list, sure it's a lot to dig through but that also helps you see what is available.

So i found an article on using custom queries. I modified the script to pull a specific tag, in this case "Open Source".

<?php 
$querystr = "SELECT wposts.* 
             FROM $wpdb->posts wposts, $wpdb->terms wterms, $wpdb->term_relationships wterm_relationships, $wpdb->term_taxonomy wterm_taxonomy 
             WHERE wterm_relationships.object_id = wposts.ID 
             AND wterm_relationships.term_taxonomy_id = wterm_taxonomy.term_taxonomy_id 
             AND wterms.term_id = wterm_taxonomy.term_id 
             AND wterm_taxonomy.taxonomy = 'post_tag' 
             AND wterms.name = 'Open Source' 
             AND wposts.post_status = 'publish' 
             AND wposts.post_type = 'post' 
             ORDER BY wposts.post_date DESC";

     $pageposts = $wpdb->get_results($querystr, OBJECT);

?>

    <?php if ($pageposts): ?>
         <?php foreach ($pageposts as $post): ?>
             <?php setup_postdata($post); ?>

             <a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title(); ?>"><?php the_title('<li>', '</li>'); ?></a>
         <?php endforeach; ?>
    <?php else : ?>

    <?php endif; ?>

If you only want to list pages for one specific tag then this would work. However, say you wanted to give a listing of pages for each tag based on the current articles listed on the page.

You might create an array of all the tags using the get_the_tags() function during The Loop and then use that array to dynamically generate the WHERE statement for the query.

You can easily use get_posts to create an array of posts based on a set of parameters. It retrieves a list of recent posts or posts matching these criteria.

In your case, I would like to show how to display your posts under a specific tag ( in your case, Tutorial ) by creating a short code, which can be easily used anywhere later on in your site.

In your functions.php

function shortcode_tag_t() {
    $uu_id=get_current_user_id();
    $args = array(
        'posts_per_page'   => 10,
        'tag' => 'Tutorial',
        'post_type'        => 'post',
        'post_status'      => 'publish'
    );

    $posts_array = get_posts( $args );

    foreach ( $posts_array as $post ) : setup_postdata( $post );
        $url = $post->guid;
        echo"<li><a href='".$url."'>" .$post->post_title."</a></li>";
    endforeach; 

    wp_reset_postdata();
}

add_shortcode('your_shortcode_name', shortcode_tag_t );

Now you have a list of 10 posts tagged under Tutorial.

Echo the created short code where ever you want to display the list.