Rule No. 1: Check a second source.
Rule No. 2: Check another source.
Rule No. 3: Check another source.
Students have to get used to looking at multiple sources when looking up information on the internet. I've come to believe this is the number one best method for finding dependable information. Adults--all internet users--have to learn to do this, and stop giving credence to the notion that just because something is published on the web it's true.
Case in point, I was looking for an ipod recently and happened upon "theipodseller dot com," to which I'm not even linking, it's so dripping with scam. The site boasts 40% discounts on various ipod models because they are going out of the ipod reselling business. The too-good-to-be-true discounts should scream scam so loudly I shouldn't have given the site more than a cursory glance, but because I wanted them to be true I gave the site enough time to do a little background check. Googling "complaints theipodseller" gave me a message board that's collecting info on Apple-related scams. Scrolling down to May 19th you see a list of reports on this site and people have posted their own research about the it, such as the whois info and mentions in articles. The gist is that the domain registrant is connected with several sites that claim to be selling other products for short periods of time and then disappearing. The thing people thought was so weird is that when you actually try to order an ipod you're only able to give them your name and email, no credit card. So my guess is that this is just a mechanism to collect emails to sell to spammers.
The moral of the story is...always get a second opinion, or more.