Best advice in this make-stuff-up-as-we-go-along world: If it sounds too good to be true, be skeptical. Do a little fact-checking. (There's goes Retiring Guy again with one of his antiquated ideas!)
New York Times reporter Paul Boutin offers these 2 websites as good places to start.
The Museum of Hoaxes (new to RG)
snopes.com (one of RG's RSS feeds)