The Help Me contributed module allows the admin to set help messages based on a path. Creating help messages is very simple, just go to Administer -> Site building -> Help and create a New help message.

Showing the help

There's three ways to use this module.

Using the $help variable
To use this option, all you have to do is add to your page.tpl.php the following:

<?php print $help; ?>

Activating the Help Me Block
To use this option, all you have to do is enable the "Help Me" block in your blocks administration page.

With the Toolbar module
If you have the toolbar module enabled, it will automatically detect the help message and show an icon with the help.

Overriding the theme_helpme()

You can override the theme_helpme() function to change the behavior of the help me module, but there's a couple of things you have to keep in mind.

<?php
function theme_helpme() {
  // This function gets the help provided by drupal, the one that modules implement by using hook_help()
  $system_help = helpme_get_system_help();

  // This function gets the custom help message, the one that this module is providing
  $helpme = helpme_build();

  // We return in $output the $system_help
  $output .= $system_help;

  // Since we get an array in help_build() we need to use $helpme['help'] to print the message
  $output .= check_markup($helpme['help'], $format = FILTER_FORMAT_DEFAULT);
  
  return $output;
}
?>

Understanding help_build()
This function will return an array in the following way:

array(
  'help', // this is the help message
  'hid', // this is the unique help message id
  'path' // this is the path associated to the help message
);