Not really to pitch but from my limited contact with tv producers I know that it's all about the pilot. A great pilot script is a work of constructed art. It needs to lay out the general premise, the characters and the world they inhabit, the overall tone of the piece, the style of the writer etc and it needs to hint at a direction of where it may go in future.
Once you have that script and want to pitch it, I presume in a face-to-face? Then It's about lauding the praises of the piece. Don't worry about selling its market or audience, the producers will be keenly aware of who will watch it. I think the number one point they want to sure about is that it will have the staying power to last. Although many tv series do not make it into a sixth season, almost all of them are commissioned with that goal in mind. And understand, detailing how your show will last that long is not about story points or episode ideas. If it's commissioned then the producers will want to stamp their own fingerprints onto the project so don't get too attached to that season cliffhanger you have in mind. You need to talk about themes and issues you can explore as the seasons go on and how you see it growing and improving. They may ask obvious questions like, "Do you think there's enough material here for six seasons?" Your answer should be yes. They already know whether there's enough material or not, what they really want to know is how much you care about the project.
Ramble, ramble. Hope it helps.