Hair, before or after rig

If I want to add hair to my model for animation, is it better to add it before or after I rig the model? Or does it even matter?

Ok, I guess what I need is a tutorial or something that explains how to set up hair to animate with a rigged character. Any ideas?

This is a very good and quick tutorial video , I prefer to do my skins and hair last but I suppose it is a personal preference , , might want to state the version of Blender you are using.