Blender 3D: Noob to Pro/Advanced Tutorials/Advanced Animation/Guided tour/Mesh/index< Blender 3D: Noob to Pro | Advanced Tutorials | Advanced Animation
This section will explain how to deform your mesh using the armature.
There are two ways to tell Blender which vertex will go with which bone: Vertex group, and Envelope.
There is also a tool useful when animating which is part of the mesh object: the Shape key, to create a preset deformation. For example: deform the face to look like a smile.