This work by Pedro Dominguez Caballero de Rodas, Jose Jaime Martin and Carmen Rio is licensed under CC BY-NC-SA 4.0
The rule of thirds
Watch the video
Composition in photography
Watch the video "Free Photography Lessons, Part 2: Composition", uploaded onto YouTube on 10/11/2008 by Jimbacsi (http://www.youtube.com/watch?feature=player_embedded&v=EFSWblaVYFs). Pay special attention to the excerpt from 2:15 to 5:15 (the bit about the rule of thirds).
If you find it difficult to understand, you can read the script here.