Multiple interloceed editable entites on on one page

I'm getting myself totally lost.

I have database model I'm happy with. I'm happy with DB design, E-R and all that. I'm reasonably sure that I've got that translated into the "has_many" and "belongs_to". Heck, its not that big a jump.

So: I have a Main parent class - Book. It has a major child class Pages. Book also has        BookAttribute settings - language, layout, rendering ....        BookAccessControl - duplicate, can_edit_pages, can_read_pages,                            can_create_pages, can_delete_pages

       Pages has content, as well as optional Attribute and AccessControl                           settings of its own that can over-ride the Book

Actually, later on, each Page will have further child tables for revisions (like a wiki, so can be rolled back), metadata - so the stories can be multi-branched, attachments for embedded images and stuff, and also forms and field - but all this will come later.

(And lets not go into making the attributes and access controls a polymorphic!)

Right now I'm trying to make an Admin page so I can build a the books and pages.

The story-board I have for the Book Admin page has a scrolling list of the books on the left. On the right there are tabs to select the child to work with.

Ultimately it would be nice to do all this with javascript, but right now I'm just trying to do a simple select and click through to another screen.

My problem is having two (or more) data entities - forms? - on th same screen.

Can anyone point me to examples of having two interlocked, editable models on screen at the same time? I would have thought this would be a fairly common situation. We see it in OS GUIs all the time.