Installing Drupal for Facebook requires a couple of small hurdles to be jumped.
Let's assume that you have already downloaded Drupal for Facebook and have uploaded the files to your modules folder (sites/all/modules). If you haven't, visit the project page and download the latest stable release. Before you activate Drupal for Facebook there are a couple of small hurdles that need jumped. If you follow these instructions, it should all fall into place gracefully. Here goes...