2: Modifiers the heart and soul of animation

One area of any 3d animation software that you should really become used to working with is the modifier section. You will use these tools more often to resolve issues related to building your objects and characters and getting parts to animate. These tools are second only to the transform tools ( Move, Rotate & Scale ).
Again one of the best tutorials comes from Oliver Villar Diz at Blendtuts.com

Blender 2.5 - How to use modifiers from Oliver Villar Diz on Vimeo.