This is the question of the year. The standard protocol is that before you contact ANY one, you put together a reel/demo. It should be short and sweet. Executive attention spans are under constant assault. That said, I'd take snippets of your two or three strongest pieces. I wouldn't go longer that three to four minutes. You want to whet their appetite and leave them wanting MORE!
It's a bit of a catch-22. It's hard to get a producer without a demo but it's hard to get a demo without a producer.
I'd set aside a budget for going into the studio to shoot your scenes properly and professionally. Make sure the audio is PERFECT and that the camera work and lighting are great too. If there are screenplays in your head or repertoire, make certain that they are in proper screenplay ot television format(s). If they're are not, typically they are tossed, unread, because it doesn't appear to have come from a professional.
If budget is a concern, of course with the internet, there are MANY outlets for uploading videos of your own creation! You could even "go viral"!!! This is a fantastic option to just try to get your voice heard. The people will spread it around if it "gets" them! So many independent artists have gotten picked up from their presence on video sites. But you'll have to do your part in sending links to your friends and supporters asking them to send it as well (but only to people they know or else its SPAM).
Get that camera hooked up!
If you're considering being a writer, once your excellent demo is complete, you may want to scout out some reputable agents to represent your work and arrange go-sees with people that can produce your work.
There are softwares available on online to guide you to the correct formats for scripts, manuscripts and screenplays.
Here is one possibility: http://www.scriptfrenzy.org
Here's a e-how article with more details about script formatting software: http://www.ehow.com/how_2195363_select-script-formatting-software.html?ref=fuel&utm_source=yahoo&utm_medium=ssp&utm_campaign=yssp_art
There's always room for new, unique, talented voices in entertainment! Now that you've found your voice, get the 'packaging' together so that you'll be taken seriously and GO for it!
There are lot of talented people in the world. Those with the talent, temperament, knowledge, proper direction and professionalism stand a much better chance in this very daunting profesion.
You've got something to offer, so GO for it! Just do it right and well.
Best wishes in your endeavor and thanks for choosing JustAnswer.
*winks and tips my hat to Ma' Chase*