Just making sure ... are you reading the Tutorial Manual (Help > Poser Tutorial Manual) or the Reference Manual (Help > Poser Reference Manual)?  Page 113 in the Tutorial Manual is about the face room. Page 113 in the Reference Manual is about the Library.

I'd try to explain, but the screen shots in the manual will probably help. The Library sections in the Poser Tutorial Manual haven't been updated yet, which is why I suspect you are looking at it rather than the Ref manual.

EDIT

Well, I'll give it a try anyway ... highlight the Poses category icon at the top, and then select the Library folder to which you want to add a new folder or pose.

--- to add a new folder, click the Create New Folder icon at the bottom of the library palette. It looks like a folder with a plus sign on it

--- to add the pose, click the Add to Library icon at the bottom of the library palette. It's just a plus sign.

These icons will NOT appear until you select a library folder in the Poses category.