Hollywood agents and studios are always on the lookout for the Next Big Thing when it comes to screenplays and each year they are flooded with unsolicited manuscripts that never see the light of day, much less one dollar of production money. Studios, production companies and talent agencies all employ young people straight out of college or with little industry experience in jobs they call Readers. These Readers go through the giant stacks of solicited material each day and try to pick out the gems in the pile. A needle in a haystack is an appropriate metaphor for these submissions. They write a review of the script which is called coverage and then either put recommend or pass on it.
The difference between an unsolicited and solicited manuscript means the difference between being read and being thrown into the trash. If you just send your script to an address (unsolicited) without having been specifically requested to do so by someone at that company (solicited) then you are wasting your time, ink, and paper. It is definitely a type of Catch-22 and nothing will put the brakes on your movie script writing career quicker than sending unsolicited scripts to studios. Agents are a different story and you might, if you are extremely lucky, get yours read and passed on to the agent who will then perhaps decide to represent you, the fledgling writer.
Another way to get your movie script writing in front of the right people is to enter one of the many screenwriting contests that are out there and actually winning one or placing in the top five. The problem is that most of these contests are scams and are only there to collect the entry fee from hapless schmucks like you. Even the legitimate contests like Scriptapalooza have pretty steep entry fees and that could be prohibitive to the rookie screenwriter with little or none of his own money.
The very best and most sure way to get your screenplay noticed and into the right hands is if you know somebody in the business. Now that somebody does not have to be Steven Spielberg or Quentin Tarantino (though it helps) but it does have to be someone with connections or a steady job within one of the studios or production houses. If you do know someone like this, dont just approach them with a script in hand. Find out first what kind of movie script writing they are looking for. If they want a romantic comedy for goodness sake do not give them a supernatural horror script. You would not believe how many times this happens.
And the number one most important piece of advice is to know the art of movie script writing inside out before you try and get one produced. Most experts agree that you should write several (more than two) screenplays before even attempting to pass one on to the studios. Although they receive a lot of material, Hollywood is still a small town and people remember a dud.