what is skinning and how do I do it?

This could have easily been answered with a google or forum search, but since the thread’s here I may as well answer…

Skinning is a getting a mesh to work with an armature- you parent the object (lets say it’s a person) to the armature, and choose “to armature”. Now you can either let it name vertex groups for each bone, or add them in weight paint mode (select the armature, go into pose mode with ctrl-tab, now select the person and ctrl-tab into weight paint mode. if you select a bone wthat doesn’t have a corrisponding vertex group, click anywhere to add that group automatically) now you can select vertices and add them to the vertex groups, or weight paint away.
For a more comprehensive answer, search for tutorials.

Alternately, skinning is the act of removing something’s skin, usually after hunting it. I don’t think that’s the answer you were looking for, though.