Given the age of this question I wanted to provide an updated answer for anyone who stumbles upon it.
I would suggest avoiding query_posts. Here's the alternative I prefer:
$child_pages = new WP_Query( array(
'post_type' => 'page', // set the post type to page
'posts_per_page' => 10, // number of posts (pages) to show
'post_parent' => <ID of the parent page>, // enter the post ID of the parent page
'no_found_rows' => true, // no pagination necessary so improve efficiency of loop
) );
if ( $child_pages->have_posts() ) : while ( $child_pages->have_posts() ) : $child_pages->the_post();
// Do whatever you want to do for every page. the_title(), the_permalink(), etc...
endwhile; endif;
wp_reset_postdata();
Another alternative would be to use the pre_get_posts filter however this only applies in this case if you need to modify the primary loop. The above example is better when used as a secondary loop.
Further reading: http://codex.wordpress.org/Class_Reference/WP_Query