That's like asking for documentation on a PC and it's applications or any micro controller for that matter. The Pi is a vary small Linux based computer that can do anything from blinking an LED to serving as the computer control system for your car, home automation project, robotics and more.

Your best bet is to look around the site, here and elsewhere, for Rasberry Pi based projects and see what other people have been doing with the board.

Can? Or will?

Try this, it's faster.

Try Raspi's own forums.