OK, here are some tutorials right here on Renderosity you should look at, they may be for earlier versions of Poser but they are still basically correct. These are mostly centered on creating Poser clothing but a clothing figure and a charater figure are basically the same thing, just in the case of clothing you "conform" it to another figure so it follows the motion. For a hoot load your Female figure (Jessi) and then load your male figure (James) and try conforming James to Jessi or vice versa.

First start here:
http://www.e-frontier.com/article/articleview/44/1/25/

Another really Great source is here:
http://istore.mikrotec.com/philc/index1.html?page=catalog&category=a&vid=668437709&pid=842974680&oldvid=2143420604

Note I bought that to start my experience in figure creation when it was still CD only, and a lot more expensive. It's been updated regularly and is a great resource for modeling as well as poser content.

Here's another free tut:
http://www.nerd3d.com/modules.php?name=Content&pa=showpage&pid=11

And here is a Doctor Geep tutorial on Joint Parameters:
http://www.renderosity.com/mod/tutorial/index.php?tutorial_id=639

A donor skeleton is used in the Setup Room, basically it is an easy way to "borrow" one figure;s CR2 to create a new one for your own figure. It'a one of the easier methods to start creating figures. Just remember that you can;t sell or distibute a figure with a CR2 that contains proprietary information (Morph targets are such info, basically any thing but the plain jane CR2 format information).

mike