In this video tutorial on After Effects CS6, we will integrate an explosion of typography into a filmed scene. We'll use the 3D tracking tool included since CS6.
As a reminder, a free tutorial dedicated to this effect is available here.

We will see how to quickly add a shadow catcher on our video, with a camera and lights to match the scene.
We will then create a text layer containing several paragraphs, and integrate it realistically on the filmed paper sheet, before making all the letters explode (in a slightly less realistic way, of course)!

For the scattering into hundreds of letters, we'll use a combination of text animations to get a dynamic and gradual explosion, triggered line by line before a stabilize state, while keeping a slight movement of levitation.
All the text remain fully parametric, and you can change the contents of the text layer on the fly.