My paperclay came in the mail yesterday (just brought mine off ebay) so today I did my first layer of clay.
To make things easy for myself and to protect my plans Ive got a piece of glass as my work top (just took mine from a cheap second hand frame). Now there's really not much to this step, its just a matter of covering the core with a thin layer of paperclay. There's no need to be fussy with this step as you can easily add and subtract from it once its dry. Also holes for the joints can easily be carved out later so don't worry about leaving openings. Then its just a matter of waiting for the clay to dry.
If you need a bit more guidance I found this video very helpful.