For famous public figures & pages, (eg. Sachin Tendulkar, Selena Gomez, ToI) you will see a blue tick mark next to the name, on their official Facebook pages. It means that the pages have been verified by Facebook as official. I am not sure how they verify, maybe they just call up, hey Sachin is http://www.facebook.com/SachinTendulkar your official page?
Here is an example