What is considered official canon?
Lucasfilm Ltd. identifies the six films of the original trilogy and prequel trilogy, and the Star Wars: The Clone Wars television series as the "immovable objects of Star Wars history, the characters and events to which all other tales must align." The following list identifies what is now considered official canon. This section may require updating as Lucasfilm releases new updates.
The Star Wars original trilogy films—Star Wars: Episode IV A New Hope, Star Wars: Episode V The Empire Strikes Back, Star Wars: Episode VI Return of the Jedi
The Star Wars prequel trilogy films—Star Wars: Episode I The Phantom Menace, Star Wars: Episode II Attack of the Clones, Star Wars: Episode III Revenge of the Sith
The Star Wars: The Clone Wars television series and film
The Star Wars Rebels television series and its supplementary source material
Star Wars Insider fiction, beginning with "Blade Squadron" in Star Wars Insider 149
Information found in the StarWars.com Databank
Information previously found in the now-defunct StarWars.com Encyclopedia
All officially-licensed source material released following the September 2, 2014 novel A New Dawn. Please see below for specific exceptions.
http://starwars.wikia.com/wiki/Wookieepedia:Canon_policy