Book: Drupal 7 Module Development (directions caused weirdness)

Question

I'm reading a book, Drupal 7 Module Development, and I'm hitting some very weird outputs.

I created a folder:

mysite/sites/default/module/first

Inside this folder I created two files.

first.info

;$Id$

name = First
description = A first module
package = Drupal 7 Development
core = 7.x
files[] = first.module

;dependencies[] = autoload
;php = 5.2

first.module

<?php

// $Id$

/**
 * @file
 * A module exmplifying Drupal coding practices and API's.
 *
 * This module provides a block that lists all of the 
 * installed modules. It illustrates coding standards,
 * practices, and API use for Drupal 7.
 */

/**
 * Implements hook_help().
 */
function first_help($path, $arg) {
    if ($path == 'admin/help#first') {
        return t('A demonstration module.');
    }
}

But when I activate the module, I get the contents of the first.module file spashed across the top of my page? Can someone advise me on what I am doing wrong?

This is my very first module for Drupal.