Drupal 7 form alter hook to easily customize the node edit form

/**
 *  Implements hook_form_alter().
 */
function MYMODULE_form_alter(&$form, &$form_state, $form_id) {
  // If you have the Devel module turned on, use this to inspect the form array
  // You can also use the form id to select a specific node type (like "article_node_form")
  // dpm($form);
  // dpm($form_id);

  // The isset() here is just to prevent PHP notices for forms where its not present
  
  if (isset($form['#node_edit_form']) && $form['#node_edit_form']) {
    // Hide the publishing options & authoring information. The defaults will be used.
    unset($form['options']);
    unset($form['author']);
    
    // Change the title of the revision fieldset, check the box by default,
    //   make sure its the top fieldset, and add a class for theming.
    $form['revision_information']['#title'] = t('Track content changes');
    $form['revision_information']['revision']['#default_value'] = TRUE;
    $form['revision_information']['#weight'] = 0;
    $form['options']['#attributes']['class'][] = 'checkbox-slider';
  }
}

1. Create a feature module
2. Drop this code into the MYMODE.module file (where MYMODULE is the feature name).
3. Modify as needed.

The cool thing is that you can use this approach to modify ANY form on the site, and you can also easily add any other hooks you like. Very simple, but very powerful.