Start pitching it to agents who specialize in screenplays, mostly being in H'wood. Clearly mark the script as "Copyright 2013 Joe Blow." REGISTER it by sending a PDF to copyright.gov. Spend the 35 bucks.
If you sell it, be darned sure to get a CA entertainment lawyer to vet the proposed contract BEFORE signing.
Licensed in Maryland with offices in Maryland and Oregon. Information here is general, does not create a lawyer-client relationship, and is not a substitute for consulting with an experienced attorney on the specifics of your situation.
Step 1 is to protect your script,. Step 2 is to find an entertainment attorney or agent to submit or "shop" your script to potential buyers/licensors. You need to start by consulting with an entertainment attorney who can do both.
Ivan J. Parron, Esq.
You need to protect your rights in the script by getting it copyrighted in your name. You can do this directly through the copyright office, and supplement your protections by joining the writers guild or other trade organization and registering your script with them. Look at http://www.wga.org/ and look under writers resources and creative rights. Then you can find an agent or attorney to shop your script.
This answer does not constitute a legal consultation, or definitive answer, nor does it establish a lawyer client relationship. Each case, controversy, or situation is factually different and requires particularized evaluation.
Step one is to read a few books that answer your question. Visit the link below.
The above is general information ONLY and is not legal advice, does not form an attorney-client relationship, and should NOT be relied upon to take or refrain from taking any action. I am not your attorney. You should seek the advice of competent counsel before taking any action related to your inquiry.
...And, if you've worked with any co-writers or editors, make sure to have proper written contracts in place. Agreements dealing with copyrights must be in writing to be enforceable. Oral agreements don't mean much in copyright law.
This content is a discussion of legal issues and general information; it does not constitute legal advice and should not be used as such without seeking professional legal counsel. Reading the content does not create an attorney-client relationship.