You can find screenplays of most of the great films in bookstores(or on line)--the great sound films, at least. There are also a number of decent books about screenwriting--I suggest buying whatever you find a a used bookstore--

The filmwriting software isn't going to teach you how to write--the books probably won't either, but they will tell you about the way that a story and a script should be structured. Films are really created by editing, though, and if you study that instead, you will actually be able to make movies--especially since, what with DV, it costs nearly nothing to shoot, and you can edit on your laptop--