Investigate the market. Watch television programs on both local and national networks to figure out what kinds of shows are popular in each genre. In creating your own show, you'll want to know what viewers want and what the networks have already purchased.
Come up with a basic concept for your show (e.g., an educational show for children that uses superheroes).
Figure out the length of time you'll need for the show. Networks will not accept a pitch unless they know how much air time to consider due to scheduling requirements.
Call or write to the networks to find out if they are accepting proposals or pitches for new shows. If the network you want to air the show declines, don't wait, hoping that the network will "come around." You may be able to have the show picked up and produced by an alternate network by the time your first-choice network changes its mind, since shows are scheduled months in advance. Use websites that list networks in order to find the contact information for the network you want.
Develop your pitch for the show. The pitch describes what the content of the show is, the kind of audience for which the show is intended, and how your show will fill a void for the network in a way that will be well-received by viewers. Figure out your log lines (one or two sentences that succinctly "sell" the concept) right away, and then expand on them.
Contact funding sources for the show. Make appointments to speak with donors over the phone or in person and use your pitch to secure production monies. Networks may be more receptive to the show if you can prove you already have interested investors.
Make appointments to pitch the show with network producers. If a network shows interest, negotiate a contract.
Hire a production staff. The staff should include a minimum of one writer, camera operators, and audio/visual editors.
Work with the staff to create a pilot episode for the show. Per your network contract and the interest showed by the viewers, produce additional episodes and provide copies to the network.