Storyboarding is the method by which many filmmakers plan the shots they will use when shooting a scene. It generally involves using hand drawings of key shots, laid out next to each other on “boards” to provide a feel for how the scene/sequence will look. Some directors extensively storyboard their films, where as others do not use it at all. Storyboarding is often used extensively in complex sequences and scenes involving visual effects, however it is pretty rare for a filmmaker to storyboard an entire film.
These days you can also get software such as Storyboard Quick or FrameForge 3D to help you construct more complex storyboards, useful if you can’t draw particularly well.