How do I get to a network with an idea for a show? I don't have any script, screenplay, anything. It's just an idea.
Here's the thing: in order to convince someone with access -- usually, a producer with a track record or a deal -- to take your idea to the network instead of their own ideas, you have to be honest about what you bring to the table. Look at it from their point of view: they've worked hard to get access to people who can buy projects. Why should they share that access with you?
Of course there are many good reasons why your idea deserves to be pitched. It's your job to make it easy for a producer to say "yes" to you. Since you don't have a script, you're not able to show them a completed property; as you said, it's "just an idea." Now, it may be a great idea, but what really sells is the execution of the idea -- or at least the promise that it can be well-executed. Since you don't have a track record or a completed (and fantastic) script, you need to be creative about what you do bring to the project.
The best thing you can bring is real-life insight. Is the idea based on something unusual that happened to you? Is your family a real-life Brady Bunch? Did you spend a year hanging out with cops on the streets of Baltimore? It was, after all, a book about just that which inspired the series Homicide: Life on the Streets and launched the author's TV career. Are you a retired CIA agent now running your own coffee shop? Whatever life you lead, you probably have some very interesting and unusual first-hand knowledge. If you alone can bring this knowledge to a TV show, well, now you have something to offer.
You can get the phone numbers of producers with deals at networks from hcdonline.com, a subscription service. Be professional and friendly when you call and remember: it's a numbers game. A lot of people will pass on the project, but you only need one "yes" to get your foot in the door.
I made the mistake of writing to CBS with an idea to revive an old show. They wrote back, from their Unsolicited Submissions Desk, that no one would even look at my idea. What do I do?
It sounds like you're not pitching a show, just suggesting they redo an old show. The thing is, there really isn't a way for you to get someone's ear for this. Sorry. First of all, the rights may not even be available. If CBS owns the property, then they probably dust it off every couple of years and go, huh, do we want to redo this? (Or, more likely, try to make a movie from it.) And so far the answer's been, no.
The wall you hit is this big force field designed to keep people from pitching ideas and then claiming the network stole the idea when something similar shows up on the air. There are only a handful of ideas in the world anyway, so something similar is bound to show up sooner or later. There are so many lawsuits about this (and some of them are justified), that the networks need to have an automatic, knee-jerk response that unfortunately kicks in for suggestions like yours that aren't really pitches.
Here's what you might do: find out (the web's a great resource for this -- try http://www.imdb.com) what production company produced the old show you liked. Then write that company (or even the actor who starred in it) a fan letter, saying how much you wish it could be revived. They'll appreciate the letter, you'll have put a bug in the ear of someone who might actually be able to mention it to someone else, and if it's at all a possibility, the ball might get rolling.
But it's a big "if." Most times, shows are a product of their time and place, and a strange combination of chemistry and talent. Luckily, more and more shows are becoming available on DVD and VHS; again, check out the web to see if your old favorites are available for rental or purchase.