Proofread your script. Your script must be 100 percent free of spelling mistakes, typos and bad grammar. Even the most sophisticated script software is not going to catch all of the errors. Spend as much time as necessary proofreading your script. It will not look professional if it contains mistakes that you could have easily fixed.
Register your script. Scripts rarely get stolen or plagiarized, but registering your script will officially document the date it was created. It will also give you some peace of mind in the rare case someone tries to steal your work. There are thousands of scripts in Hollywood in the hands of many different people. You must feel comfortable with your script being read by many readers. The Writers Guild of America will register your script for a small fee. Alternatively, you can copyright your script with the U.S. Copyright Office at the Library of Congress.
Research agents and production companies. Agents rarely accept unsolicited scripts. Big production companies are simply too busy to read every script that enters their office. Save yourself some frustration by doing some research. There are many fine screen trade books on the market and websites on the Internet that list agents and companies that are willing to accept queries from writers.
Prepare a superior query letter. Impress a prospective agent or production company with a well-written, succinct query letter that includes the logline of your script. A logline is a brief two or three sentence concept of a script. Concentrate on writing a perfect logline -- make it leap off the page. If the agent or production company is interested, they may ask you to submit a detailed synopsis, a treatment (a five to 10 page summary of your script) or your entire script.
Contact the agent's office with a follow-up phone call. Intimidating as it may sound, cold calling an agent's office to inquire about your query letter may unearth it from a pile of other letters. Agent and production company offices are notoriously busy. Although you may impress them with your fortitude, if their answer is "no" after reviewing your work, don't be a pest. There is a fine line between being persistent and being a pest.
Pitch it in person. If an agent or production company has expressed interest in your script, they may ask you to "pitch" it to them in their office. A pitch is a brief presentation where you get to promote your script. Although this experience can be daunting for some, it is important to remember that if the agent or production company weren't interested in your script, they never would have requested that you do a pitch.
Enter script contests. If you get frustrated with being unable to get a toe in the door of Hollywood, contests are an option. Screenwriting contests have grown exponentially in recent years. Some contests offer cash prizes; some offer to shop your script to agents and production companies; and some offer a combination of both prizes. Invest some time in researching which ones may be right for you.