hook_permission() is a handy way to allow certain roles to access certain pages, i.e. the 'Administrator' to change settings and say 'Comms Team' to view the results. As per a lot of Drupal building the return value must be a nested array, and that can be tricky to remember... So here is an example.

/**
 * Implementation of hook_permission().
 */
function MY_MODULE_NAME_permission() {
  return array(
    'view MY_MODULE_NAME' => array(
      'title' => t('View MY_MODULE_NAME'),
      'description' => t('Allow certain roles to view MY_MODULE_NAME without control of the settings.'),
    ),
    'administer MY_MODULE_NAME' => array(
      'title' => t('Administer MY_MODULE_NAME'),
      'description' => t('Add, delete and edit the settings for MY_MODULE_NAME.'),
    ),
  );
}

Simply replace MY_MODULE_NAME with the 'machine' name of your module.

Text that appears inside the t() function can be a 'real' name rather than the 'machine' name as this is just text to be displayed on the 'permissions' page.