Your going to need an API to connect into the facebook model, there are quite a few available
http://wiki.developers.facebook.com/index.php/User:ASP.NET[
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I've used 'Facebook.Net' before which was quite easy going
http://facebooknet.codeplex.com/[
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Can't remember all the ins and outs, but pretty sure you're going to have to add the 'Developer' application to your facebook account + create an application to generate an API Key & Secret. You then use these within the Facebook.Net API to allow connections and access to facebook information.
Loads of reading material available on the facebook developer wiki site
http://wiki.developers.facebook.com/index.php/Demos[
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