Observation: How do you determine the credibility of the online information? How do you know the information is factual?
The best way to determine the credibility of a website is usually just checking the URL. Anything ending with a .com is questionable, but can still be accurate. The best informational sites are .edu and .gov, and even a .org doesn't hurt to use every now and then. A website should cite its sources for referencing (shows confidence in information), and when using a site that anyone can post to (Wikipedia, Yahoo Answers, etc.) you should always copy and paste the information you find in to a search engine to see what it pulls up. If multiple results exist that agree, you are probably safe. With Wikipedia, chances are that someone literally copied the text of another site, so it's typically easy to cross-reference. If you can't find any agreeing sources, I would think twice before using the questionable information. Lastly, articles written for various sites have different credibility. The Huffington Post, for example, has a reputation as a very credible and respected source of information, while a site like nationalenquirer.com is probably not a good starting point. Or ending point. Or any point at all. Just look for the credentials of the author at the end of the article. If it says "Jill Smith, Inquiring Writer", you've found no credentials. If it says "Jack Waters, Ph.D MD..." etc. you've probably found somebody who knows what they're talking about.