Credibility is defined in one single word: believability. If the person is credible then they are credible people, if the website is credible then this means that their information is believable. The majority of web users look for sites which are credible, that have information which are believable.
The two main factors which can identify a web site as a credible one are:
1. The website is trustworthy. This means that the website is honest, truthful, contains unbiased information, has good intentions all around and is ethical as well as moral. In short, it is not out to scam the visitors for the sake of money.
2. The website is known for its expertise in the category that it is in. if it is categorized purely as an information site, then they should contain articles which are written in the most knowledgeable, experienced and competent manner.
Based on the two factors above, the web users will be able to intelligently weight the credibility of the site they are visiting. Unfortunately, once there are a series of comments where the readers were disappointed despite the credibility of the site, this could adversely affect it.
This is the reason why it is best that those who manage the sites are people with integrity. They have to continuously upgrade the information in the websites so that it is up to date and "with the changing times". It would not be a good idea to leave information that is more than six months old in the site for there are a lot of things that can change during that time.
Generally, users of the internet will only continue to go to the sites which they can bookmark as favorites. This way, they can just click and the site loads up. This also makes it easier for the websites to know that their page is ranked high and highly visible on major search engine results pages.