Using the code given here you can display five posts in random order on your WordPress Site.
About the format you can adjust as you like, the number of posts is set by numberposts=5
<?php $rand_posts = get_posts('numberposts=5&orderby=rand');
foreach( $rand_posts as $post ) :
<a href="<?php the_permalink(); ?>"><?php the_title(); ?></a>
<?php the_excerpt() ?>
<?php endforeach; ?>