Let you try with this code. Clear performance cache.

    function example_block_info() {
      $blocks['my-block-id'] = array(
        'info' => t('Block Name'),
      );
      return $blocks;
    }
     
    /**
     * Implementation of hook_block_view().
     */
    function example_block_view($delta='') {
      $block = array();
      switch ($delta) {
        case 'my-block-id':
          $block['subject'] = t('Block Name');
          $block['content'] = example_contents();
          break;
      }
      return $block;
    }
     
    /**
     * custom html block
     * @return string
     */
    function example_contents() {
      return '
        </p><div class="body">
          Hello World, this is a example custom Block
        </div><p>
      ';
    }

For more info see this http://www.summasolutions.net/blogposts/how-create-basic-block-code-new-drupal-7