I would start here:
but like ws6vert said in the other thread...skinning is the one area we let fall behind with all of the new development. Theres a lot planned to make it quite a bit easier but we haven't had time to work through it yet. If it comes down to it, you can mock things up in gimp or photoshop, break it up into individual images, and I can turn it into a plugin for you.
As far as the media skin....any chance you have a google wave account?