Im wondering if anyone could give me some advice, or point me to some tutorials about mapping out a game before dev. What are some of the key considerations, layouts, standard practices etc?

I'm wanting to make a level/area game, so there will be many backgrounds, would it be best to keep them on the same .fla or import them to keep size down?
also I am going to be keeping score and allowing saves, can those be done if I'm importing files?

Thanks

Mark