Wickd89.... if you can find the Jack Olson GQ article from a couple of years ago, maybe it is online somewhere or Olson can get it for you...it would probably show a few things about how the industry works. Lots of the top stars will only work with their chosen writers and even if they get a good script, often their writer will step in and do a re-write and the original screenwriter gets pay but no credit... as with most things in life, it takes persistance and contacts to get something actually going....
in the opposite direction of that are screenwriters who have taken it upon themselves in an entreprenerial sense...to finance and possibly direct their own projects.... (aka 'pulling a Tarentino') this works particularly well for the indy-film type of thing...and if it is good...then can get into some of the festivals etc. and generate some buzz...but you will need some level of financing and some contacts to get that done...
Here is a great link on screenwriting that you can find a ton of great advice and columns...these 2 writers, Elliott and Rossio....started out like you and i...didnt have anything going other than their work and persistance and now they have quite a few films under their belt, including Pirates of the Carribbean etc. They are totally honest and candid on this great website... link:
http://www.wordplayer.com/
In addition...read lots of scripts to get familiar with the format, and maybe take some acting classes so you can actually work through some dialogue (and you will find that most written dialogue sucks lol!) and when you act it with other people...you find yourself thinking about rewritting the garbage on the spot...but you usually cant! good experience though...
Like you I have some ideas.... the one script that I have started is a comedy-farce that is very much in the Will Ferrell vein... Ive got that one sketched out and work on it from time to time... the other idea takes place in the early 70s 'Easy Rider' in a roadside bar type feel..
with the musical projects and composing that im involved in though, i have little time to spend on these... unfortunately...