'page', 'post_per_page' => '5' );
$loop = new WP_Query( $args );
if ( $loop->have_posts() ) : while ( $loop->have_posts() ) : $loop->the_post();
$image = wp_get_attachment_image_src(get_post_thumbnail_id($post->ID, "best_cover", true));
?>
Setup your slides in the admin area by using the "Page" and "set featured image", we'll take care of the rest!