Zosia Korcz has written this detailed tutorial on getting started with Phaser. In it she takes you through setting things up and then builds a sliding puzzle game:
"As you probably already know, Phaser is one of the most popular free JavaScript frameworks made by Photonstorm. Its purpose is to help developers to create HTML5 games really quickly, by providing a set of tools which handle generic tasks; like loading images, game loops, inputs, physics; needed to program the game. With these taken care of, the developer can focus on their game idea, not wasting a time on rewriting or copying the same code between previous projects."