Digital signage questions

Hi everyone,
Recentelly in my work they have install LCD plasma screens on the walls for internal displays.
As first time I am doing this kind of design with Flash what size must be(Pixels) in the documents properties my flash document so they can fit on screen?
Also Do I need preloader for this kind of display into my flash documents?
And my last question how I can put together to play in some order different flash designs?

Thanks