Anyone--I repeat, anyone--can publish anything to the web. If you aren't convinced, try a Google search on "martin luther king" and look through the first few links. At least one of them is published by white supremasists who use lots of information out of context to besmirch the reputation of this great man. (Sorry, I refuse to link to it from here because that just drives up their Google listings!) So, one of the most important roles for the media specialist is helping students to evaluate information they find on the web. Luckily, there are lots of resources to use. I would start with Kathy Schrock's The ABC's of Website Evaluation that includes survey forms as well as sample sites to use for practicing their skills.
Here are two websites to test your ability as an evaluator. Whic one is the REAL World Trade Organization website?
You can use a service called WhoIs to find out who owns websites. I usually use the interface from Network Solutions.
The American Library Association's Booklist website offers reviews of books, software and websites.
The Southern Regional Education Board offers evaluations of websites and software.