I've read the Walsh newsletter, and while I think it performs a good service, I'm somewhat concerned about its accuracy at times. One of the things his group is successful about doing is to organize national boycotss against companies that advertise on programs that portray questionable activities and language, which is a good thing.
Another thing that can be done locally is to make know to your local stations what you like and don't like about their newscasts. Letters and phonecalls.
Of course children need to be taught to question what they see on TV and to understand that it isn't "fact" but is someone's opinion. But this all depends on their ages and maturity level. There have been towns that pressured their local stations to not put on so much crime news, and to be more responsible about the news stories they portray -- to include them in a context. )For example, because blood and guts attracts viewers, such stories are often put on without explanation and viewers get the impression that murder is rampant. But many of the murders are gang warfare and vendettas, meaning that it's not random attacks but part of an underworld lifestyle.)
There's a famous story about Orange County going bankrupt but nobody there knew that the budget was in trouble because reporters didn't talk about the budget because viewers found it too boring. So the federal government had to bail out one of the wealthiest counties in the country! And in Chicago, they tried to do a serious newscast that avoided sensationalism and that looked more like the news of our childhoods, but despite its high quality, its ratings fell and after 8 months the network canceled it. So we all need to honestly ask ourselves if we're willing to suffer through boring talking heads and understand complicated issues or are we also part of the problem.
As I said before, I get news from public radio and usually just watch American Movie Classics and Twilight Zone reruns.