functions.php

<?php

/**
 * Include products in the blog homepage
 *
 * @author Bill Erickson
 * @link http://www.billerickson.net/customize-the-wordpress-query
 *
 * @param object $query
 */
function be_blog_query( $query ) {
	if( $query->is_main_query() && $query->is_home() && !is_admin() )
		$query->set( 'post_type', array( 'post', 'products' ) );
}
add_action( 'pre_get_posts', 'be_blog_query' );