There was a Firesign Theater album "Everything You Know Is Wrong" that came out in the 70s. It was not that funny, not their best work. It was mostly just cynicism and mockery. I thought of the title when Maggies's linked to Real Clear Politics' What If Everything You Know Is Fake? The article operates mostly from one point of view, but it is a good general question to ask. I say that you and your sources are unreliable, you say that mine are. In nine cases out of ten, neither of us knows that much about the subject in question, but we have reasons for choosing the sources we do. What to do, what to do?
We can start by looking carefully at who is fighting fair. While the side that is more nearly correct in an argument might not be morally superior in any way, all of us try to put our best arguments forward, not our worst. I assume that people would use good arguments if they knew them. If they thought the statistics were on their side, they would appeal to those. The advice to lawyers to 1. Argue the facts, 2. Argue the law, 3. Pound the table is actually what most of us do, though likely not so obviously. If they are pounding the table, I want to know why.
Who is being insulting, openly or slyly? Who is changing the subject rather than answering? Who is appealing to social popularity rather than reason, or emotion rather than reason? Who is listening and responding to the arguments given, who is pretending that they can summarise the opponets' arguments in a vicious way?
There are sites about logical fallacies. Fine. But the fallacies are nearly always escorted by simpler infractions or cheap shots. There are arguments over who is an authority and who is not - because lots of people appeal to authority, but define it differently. Yet those arguments also seem to devolve into accusations of bad faith very quickly as well.
There are many subjects I don't know much about, yet feel confident forming an opinion about anyway, because of my experience with the styles of argument on the topics I do know something about.
It's not actually very hard. One doesn't need to be overwhelmingly bright or learned - not in theology, not in science, not in politics, not in understanding human nature. Just be willing to look at who is fighting fair - not in the best, protected enclaves, but in the arena of competing ideas. You can even do it in foreign languages you barely understand, in a pinch.
Fighting fair tells you what you need to know 90% of the time.