Howard Rheingold, the author of Smart Mobs, looks at several different media literacy issues: determining authority, avoiding scams and getting good information. Crap Detection 101 is also an expansion of an article that he wrote for the San Francisco Chronicle (and which is still available online). He uses examples and tells brief stories to illustrate his point. He is also very kind: he know these topics are difficult and when people are sucked in, they feel stupid, as well as vulnerable.
I would recommend this resource to anyone who is timid about using some of the services on the Internet that make us more efficient, but who is worried, either because of a past mistake or because of the media, that they will be conned. His tips could also be applied to looking critically about corporate information and job scams. Crap Detection 101 may also help Internet risk-takers, though Rheingold's low key manner may not be enough to grab their attention.