There are a lot of ways to break into TV writing, but what follows is what you might consider the basics steps on how to become a TV comedy writer.
Step 1: Study the TV Format
If you haven't already, the first thing you need to do is to make sure you understand the structure of TV comedy. Whether its a sit-com (e.g., Two and a Half Men, My Name is Earl) or a drama-dy (e.g., Sex in the City, Ugly Betty), half hour or hour, you need to get clear on how the show is broken down. Is it a 2 or 3 act structure? Does it have a clear A story? B story? Runner? If you dont know what Im referring to here, you may want to start by reading a few books on script and story structure. This will help you to understand the basics of scriptwriting.
You should also start to learn about how a television show is produced. What is an executive producer? What does a showrunner do? Understanding how a television show goes from an idea to your television set is good knowledge for you to have.
Once you have a sense of how a show is produced, how a TV script is written and what the basic structure of your favorite show is, youre ready for Step 2.
Step 2: Write a Spec
Now you need to show the industry that you can actually write by writing a spec script. The same way an artist or photographer has a portfolio, a writer has a collection of samples that he or she can show a potential employer.
So, what is a spec script? Technically, a spec refers to a speculative script. Youre writing it for free and speculating that someone will read it and hire you. (See, How to Write a Spec Script) Its essentially a sample script that is either of an existing and popular TV comedy (e.g., The Office, Two and a Half Men) or a piece of original material that highlights your ability to create voice, situations, characters, and ultimately, tell a story. Keep in mind, that if you want to be a comedy writer, then whatever piece you use as your spec script should at the very least be funny.
Tip: Write a spec of a popular show. After all, it wont do you much good to write an episode of a TV comedy that only a handful of people are aware of.
Now, it used to be that if you wanted to be a TV comedy writer, you would simply write up a spec or two of your favorite shows, send them in to an agent and hopefully impress them enough to inspire them to go out and find you a writing job. Things have changed a bit since then and even then, it was never quite that easy. The industry (meaning potential employers) is much more open nowadays to reading different types of material.
A lot of the shift has to do with the fact that there just arent as many comedies on the air as there used to be. That said, its recommended that you write at least two spec scripts: one script of a popular TV comedy and one original pilot concept.
Its a bit more work, but it gives people the chance to see that you can not only recreate the character voices and story dynamics of an existing show, but that you can create your own voices, characters and storylines that are unique to you. Some writers balk at the notion of having to write an episode of an existing show but consider that the job youre going after is exactly that. So, if you show people you can do it, youll dramatically help your chances of getting to do it.

