Define your idea for your show. Be sure you're clear on the type of show you want it to be. Once you have your idea, put together a logline. A longline is a short paragraph that gives a synopsis of your idea. Your logline shouldn't be more than 30-40 words long and should give the reader a general idea of what your show will be about.
Give your show a format. The show's format is the premise that moves it forward. For example, if you want to do a show about dancing, your format could be that the contestants would have to work in teams to develop dance routines. Once the winning team is chosen, the people from that team would compete with each other for the grand prize.
Put your idea on paper. Create a simple document that includes your logline, format and how the show would resolve.
Locate a list of networks that are looking for shows. The Hollywood Creative Directory is a good place to start. This will give you a comprehensive list of networks and producers who are actively looking for show ideas, as well as their contact information. This will help you determine which networks may be a good fit for your show. You also can use social networking web sites like Tvwritersvault.com to connect with people who may be interested in your show.
Submit your idea. Once you have narrowed it down to a few networks or producers, use the contact information you've obtained to contact that person by mail, email or phone.