https://developers.facebook.com/blog/post/465
You can publish stories to people who like your page with an open schedule, just as you write a Facebook message from your wall. Stories appear in news feeds of people who clicked the Like button on the Open Graph page.
You can also publish using our API. If you link your Open Graph page to your Facebook application using the fb: app_id meta tag, you can post updates to users who like your pages using the graphical API.
First you need to get an access token for your application.
Post a blog post, it covers everything you need.
source share