Create your Facebook Ad here http://www.facebook.com/ads/create/
When you click the link above you will have 3 step by step process for creating your facebook ad or sponsored story.
Make sure you are logged into facebook when you click on the link this will allow you to manage the ads from your profile page and make features more central. For a more detailed step by step with pretty pictures click here: http://www.facebook.com/business/connect
