Many of our writers ask for advice on what screenwriting software to use and questions about margins, dialogue, scene headings etc. While proper formatting is definitely important, it's obviously secondary to the quality of your story. I've seen many scripts with odd formatting that have gone on to be produced with major stars.
The Academy of Motion Picture Arts and Sciences has a fantastic, perfectly formatted screenplay about screenplay formatting.
If you're looking for a free template for Word or Google Docs check out this blog post from Arc Studio: Free Screenplay Template for Microsoft Word and Google Docs
Click this image to check it out:
While Final Draft is the industry standard software for screenwriters, it's not cheap. Celtx is currently one of the most popular free screenwriting software and they also have a collaborative browser-based service which is gaining a passionate user base. Movie Magic and Adobe Story are also popular applications.