First I would say that you need to learn about how to create and edit a "Story Board" in Blend.
then you can attach them to Events or to code behind.
Storyboards are used in WPF and Silverlight to describe a set of transform steps of a visual on the screen from one state to another and use a timeline to control the speed and make sure that at runtime you get a smooth flow between states.
for example you could make a picture appear starting as a tiny square and zoom larger while spinning around until it stops at 100% size and is upright on the screen. you can time the process to take say 2 seconds.
if it's to slow the blend editor can allow you to adjust the timeline to run faster but still end up with the picture upright and at 100% size when it finishes.