...
Storyboards come in many different flavors but the main ingredients are pictures and text that describe how a user accomplishes a task. Most designers recommend starting on a whiteboard or some other low tech technique that allows you to draw and make changes quickly. Storyboards may contain pictures of the user using the product or for many web sites and applications you may only want to include the screens.
Examples:
Simple Text Inline Edit Storyboard
Uploader Storyboard - Simple Upload
Uploader Storyboard - Upload and Cancel
Date Time Picker Storyboard - Editing a selected date
Why use storyboarding?
Storyboards enable working out the interaction details in the context of users getting their work done. It can be a low cost method to work out designs from very early in the process to developing the final minute details. Storyboards are also a great communication tool for describing how the system should work to implementers and how it does work to users.
...