Here are two metholds that you can use to list your related posts on your blog.

The first method

Display related posts in single post and Rss Feed.

Drop the code into your theme’s functions.php file:

function wp_get_related_posts()
{
global $wpdb, $post,$table_prefix;
$limit = 10; //How Many Related Posts Displayed
if(!$post->ID){return;}
$now = current_time('mysql', 1);
$tags = wp_get_post_tags($post->ID);
$taglist = "'" . $tags[0]->term_id. "'";
$tagcount = count($tags);
if ($tagcount > 1) {
for ($i = 1; $i < $tagcount; $i++) {
$taglist = $taglist . ", '" . $tags[$i]->term_id . "'";
}
}
$limitclause = "LIMIT $limit";
$q = "SELECT p.ID, p.post_title, p.post_date,  p.comment_count, count(t_r.object_id) as cnt FROM $wpdb->term_taxonomy t_t, $wpdb->term_relationships t_r, $wpdb->posts p WHERE t_t.taxonomy ='post_tag' AND t_t.term_taxonomy_id = t_r.term_taxonomy_id AND t_r.object_id  = p.ID AND (t_t.term_id IN ($taglist)) AND p.ID != $post->ID AND p.post_status = 'publish' AND p.post_date_gmt < '$now' GROUP BY t_r.object_id ORDER BY cnt DESC, p.post_date_gmt DESC $limitclause;";
$related_posts = $wpdb->get_results($q);
$output = "";
if (!$related_posts)
{
$output .= '<li>No Related Posts</li>';
}
foreach ($related_posts as $related_post )
{
$dateformat = get_option('date_format');
$output .= '<li>';
$output .= '<a href="'.get_permalink($related_post->ID).'" title="'.wptexturize($related_post->post_title).' ('.mysql2date($dateformat, $related_post->post_date).')">'.wptexturize($related_post->post_title).'</a> ('.$related_post->comment_count .')';
$output .= '</li>';
}
$output = '<h3>Related Posts</h3><ul>' . $output . '</ul>';
return $output;
}
function wp_related_posts_attach($content)
{
if (is_single()||is_feed())
{
$output = wp_get_related_posts();
$content = $content . $output;
}
return $content;
}
add_filter('the_content', 'wp_related_posts_attach',100); 

The second

Display related posts only in single post. 

Insert the following code into your theme’s single.php file(usually after the line <?php the_content(); ?> ):

<h3>Related Posts</h3>
<ul>
<?php
$tags = wp_get_post_tags($post->ID);
if ($tags) {
$first_tag = $tags[0]->term_id;
$args=array(
'tag__in' => array($first_tag),
'post__not_in' => array($post->ID),
'showposts'=>10,//Display 10 related posts
'caller_get_posts'=>1
);
$my_query = new WP_Query($args);
if( $my_query->have_posts() ) {
while ($my_query->have_posts()) : $my_query->the_post(); ?>
<li><a href="<?php the_permalink() ?>" rel="bookmark" title="<?phpthe_title_attribute(); ?>"><?php the_title();?> <?php comments_number(' ','(1)','(%)'); ?></a></li>
<?php
endwhile;
}
}
wp_reset_query();
?>
</ul> 

source

1.The simplest but quickest way

Add this line below to your theme’s footer.php file：

Copyright&copy; 2011. <a href=www.wooshift.com>WooShift.Com</a>

You need to modify the date 2011 to what suits you.
Output format：

Copyright © 2011 WooShift.Com

2.using A php “date()” function

Add this to the footer.php file:

Copyright &copy;<?php echo date('Y'); ?>.<a href="<?php echo get_option('home'); ?>"><?php bloginfo('name'); ?></a>

Copyright &copy;<?php echo date('Y'); ?>.<a href="<?php echo get_option('home'); ?>"><?php bloginfo('name'); ?></a>

This code above will automatically update your copyright date every year.
Output format：

Copyright © 2012 WooShift.Com

3.copyright notice from the year your blog started to the current year

Add this to the footer.php file:

Copyright &copy; 2011-<?php echo date('Y'); ?>.<a href="<?php echo get_option('home'); ?>"><?php bloginfo('name'); ?></a>

Output format：

Copyright © 2011-2012 WooShift.Com

4.using functions.php file

Open your theme’s functions.php file and insert the code below in it：

function copyrightDate() {
	global $wpdb;
	$copyright_dates = $wpdb->get_results("
		SELECT 
			YEAR(min(post_date_gmt)) AS firstdate, 
			YEAR(max(post_date_gmt)) AS lastdate 
		FROM 
			$wpdb->posts
	");
	if($copyright_dates) {
		$copyright = "Copyright © " . $copyright_dates[0]->firstdate;
		if($copyright_dates[0]->firstdate != $copyright_dates[0]->lastdate) {
			$copyright .= '-' . $copyright_dates[0]->lastdate;
		}
		echo $copyright . " " . get_bloginfo('name');
	}
}
add_filter('wp_footer', 'copyrightDate');

Save the functions.php file and your copyright notice will automatically update every year.

Output format：

Copyright © 2011-2012 WooShift.Com