Create an idea for a television show. The first step in doing this is to create a logline. This is a one-sentence summation of your show. Without this you won't be able to pitch the rest of your idea.
Write your pitch as a treatment. This outline of your show can be anywhere from one to 10 pages long. If you have no experience creating a television pitch, you should include as much detail as possible. The treatment contains the logline, character introduction and ideas for sample episodes. The treatment often also includes an outline for the pilot story; this is the first episode of the show. You may not need to provide a treatment if you are doing a verbal pitch, but a production company may want you to submit one if they like the idea.
Protect your treatment by registering it with the Writer's Guild of America. You can also do what is known as a "poor man's copyright" by simply putting your treatment in a self-addressed stamped envelope and mailing it to yourself. When you receive it, do not open it. The postmark acts as your legal protection.
Contact a producer with a development deal for NBC studios. Search the Hollywood Creative Directory for NBC Studios. Under their listing, NBC will usually list all of the producers and productions companies that have deals with them. The studio and the network operate independently. A show produced by NBC studios does not necessarily have to air on NBC network. However, the network has an obligation to solicit material from these producers first. You will have to convince one of these producers that your material is worth turning into a show. They will partner with you and help present it to the network
Contact a television production company that has a show airing on the NBC network. Watch the end of a show that you enjoy on NBC. At the end credits you will see a production logo. This is the production company that produces the show. Search the Hollywood Creative Directory for the contact information of the production company. Contact them and see if they will listen to, or allow you to send them, your pitch. Networks aren't obligated to listen to these producers, but do so out of courtesy.
Read Entertainment industry trade magazines such as The Hollywood Reporter and Variety. Also read blogs that specialize in the entertainment industry. These sources at times have information about open-submission opportunities at NBC.
Attend a writer's conference attended by NBC production executives. If you are fortunate enough to get one of them to interact with you, pitch them your show. Have your treatment with you in case the executive wants to hear more.