I cannot understand the FB API. I feel the problem is because I cannot understand the protocals OAouth draft page (source, page 19). Well firstly it was so but now I understand that OAouth 1.0 and OAuth 2.0 are totally different protocols although for the same goal, apparently..
Perhaps the most essential stuff are FB docs about authentication here and a blog post here. I am trying to categorize here threads to dig deeper into the FB API.