two columns of posts on homepage, one of them “favorites”

I think you are hearing “crickets” because there are several component to this. You need to:

1. Create a meta_box
2. Save data from that meta box
3. And build a Loop on the front

For #1 and #2:

function add_featured_meta_box() {
  add_meta_box("featureddiv", "Featured Post", "featured_post_meta_box", 'post', "side", "low");
}
add_action("do_meta_boxes", "add_featured_meta_box");

function featured_post_meta_box(){
  global $post;
  $custom = get_post_custom($post->ID);
  $featured = (!empty($custom["_featured"][0])) ? $custom["_featured"][0] : ''; ?>
<table>
    <tr>
        <td>Featured
        <td> <input type="checkbox" name="featured" <?php checked($featured,true); ?> /> </td>
    </tr>
</table><?php
}

function save_featured_meta($postid,$post){
  global $_POST;
  // set the ID to the parent post, not the revision
  $postid = (wp_is_post_revision( $postid )) ? wp_is_post_revision( $post ) : $postid;
  $post_type = get_post_type( $postid );
  if (isset($_POST['featured'])) {
    update_post_meta($postid, "_featured", true);
  } else {
    delete_post_meta($postid, "_featured", true);
  }
}
add_action('save_post', 'save_featured_meta', 1, 2);

And for #3:

$args = array(
  'post_type' => 'post',
  'ignore_sticky_posts' => true,
  'meta_query' => array(
    array(
      'key' => '_featured',
      'value' => true,
    )
  )
);
$query = new WP_Query( $args );

Barely tested. Possibly buggy. Caveat emptor. No refunds.