• http://drupal.org/node/206753 Creating modules - a tutorial: Drupal 6.x
• http://api.drupal.org/ API documentation
• Drupal-Hooks
• http://drupal.org/node/416986 How to create a simple Drupal 6 module in three easy steps
• http://www.packtpub.com/article/creating-our-first-module-using-drupal6-... Block
• Drupal-Schnipsel
• Blöcke in Drupal

Vorgehensweise

1. shortname (lowercase)
2. sites/all/modules/modulename
3. modulename.module:
   
   <?php
// $Id$
4. omit the closing ?>
5. Hooks: {modulename}_{hook}
6. modulename.info:
   
   ; $Id$
name = Module name
description = A description of what your module does.
core = 6.x
7. description ohne linebreaks, max. 255 Zeichen, keine Sonderzeichen (aber HTML-Entitäten), keine Anführungszeichen
8. optional: dependencies[] = anderes_modul
9. hook_help:
   
   /**
* Display help and module information
* @param path which path of the site we're displaying help
* @param arg array that holds the current path as would be returned from arg() function
* @return help text for the path
*/
function onthisdate_help($path, $arg) {
  $output = '';  //declare your output variable
  switch ($path) {
    case "admin/help#onthisdate":
      $output = '<p>'.  t("Displays links to nodes created on this date") .'</p>';
      break;
  }
  return $output;
} // function onthisdate_help
10. mehr Info: http://api.drupal.org/api/function/hook_help
11. hook_perm:
    
    /**
* Valid permissions for this module
* @return array An array of valid permissions for the onthisdate module
*/
function onthisdate_perm() {
  return array('access newmodule', 'create newmodule', 'administer newmodule'); // ein Wert genuegt
} // function onthisdate_perm()
12. hook_block:
    
    /**
* Implementation of hook_block
* @param string $op one of "list", "view", "save" and "configure"
* @param integer $delta code to identify the block
* @param array $edit only for "save" operation
**/
function onthisdate_block($op = 'list', $delta = 0, $edit = array()) {
if ($op == "list") {
    // Generate listing of blocks from this module, for the admin/block page
    $block = array();
    $block[0]["info"] = t('On This Date'); // "info", "cache", "weight", "status"
    return $block;
  }
} // function onthisdate_block
13. hook_block erweitern:
    
      else if ($op == 'view') {
    // Generate our block content
    // Get today's date
    $today = getdate();
    // calculate midnight one week ago
    $start_time = mktime(0, 0, 0,
       $today['mon'], ($today['mday'] - 7), $today['year']);
    // we want items that occur only on the day in question, so 
    // calculate 1 day
    $end_time = $start_time + 86400;
    // 60 * 60 * 24 = 86400 seconds in a day
    // set up the block
    $block = array();
    $block['subject'] = 'On This Date';
    $block['content'] = $block_content;
    return $block;
  }
14. admin_funktion
15. hook_menu (siehe auch http://api.drupal.org/api/function/hook_menu/6)
16. onthisdate_admin_validate (mit Suffix _validate)