I highly recommend just doing a film to all the writers out there including you AM217 (welcome to the forums BTW!). With me, at least, I found doing a sort film absolutely gave me a taste of what it's like in the actual field and damn if it isn't cut throat. Your cast. your crew. your producers (everyone has egos that they feel need stroked) everyone wants a piece of you and I actually directed wrote/ or co-wrote the script and stared in my two short films for my fim school class. Everything was riding on me and things have to be changed, things have to be completely removed, you have to have filming locations etc... it's a huge undertaking but it is also great fun if you love what your doing (it helped that my films were dark comedies and my costars where hilariously funny)
That said, I guess what I mean is anyone wanting to write a script would find it very humbling and neccessary to see the whole puzzle and not only study screenwriting but also directing, lighting, sound, etc...
Hope that helped some AM217 and everyone really.