I am trying to display new custom post and the default post as well.
How to display both posts(default,my_custom_post)
<div id="primary" class="site-content">
<div id="content" role="main">
<?php wp_list_pages('title_li=');
wp_nav_menu();?>
<?php if ( have_posts() ) : ?>
<?php /* Start the Loop */ ?>
<?php while ( have_posts() ) : the_post(); ?>
<?php get_template_part( 'content', get_post_format() ); ?>
<?php endwhile; ?>
<?php twentytwelve_content_nav( 'nav-below' );
?><?php else : ?>
<?php wp_reset_query();
query_posts('post_type=my_custom_post'); // my custom post
?>
but only single post is displaying yet.
This is how you display custom posts in wordpress.