Installation for Drupal 5.x

1. Patch the comment.module at modules/comment/comment.module with the 
   file comment_notify_patch_to_comment.patch.  If you are unsure how to
   apply patch files please read http://drupal.org/patch/apply or simply 
   open the file and manually take the actions that it shows.  For Drupal6.x
   the patch was accepted and this is no longer necessary.

   Note: When you upgrade Drupal core you will need to re-apply that patch 
     to keep this module working.

2. Enable module on the Administer > Site Building > Modules

3. Configure the settings for comments, especially
    -comment moderation on/off
    -users must leave their contact info (set to yes, or how shall we mail them?)