Unfogged: the typical way I look for a fact online is Googling a couple of keywords, and then clicking on a selection of the top ten results for a site that looks 'credible'. Sometimes I won't find a credible looking source, and then I rephrase the search or give up, rather than take what I get from something that looks less reliable.
I'm having trouble quantifying 'looks credible' for her, though. I mean, I think whatever rules of thumb I use are pretty solid -- I don't find myself relying on some website and then embarrassingly discovering that it was written by some idiot inventing the whole thing. But I rely on things like graphic design and layout, which I can't make myself pass on to Sally with a straight face ("You can believe anything you read on the Internet if the background is white or offwhite, accent colors are unsaturated blues or warm earth tones, and nothing on the page flickers.") And of course there are things like institutional affiliations and so forth. But it's all hard to describe in seven-year-old terms.
So, anyone have some good rules of thumb for how to identify a credible website?
Perhaps the scariest thing is that I experience no cognitive dissonance as I regard somebody who calls herself "Lizardbreath" as a credible, authoritative source...