Anyone can publish information on the internet and therefore you should always assess the quality of a website. When assessing a website, note especially the following:
Can you identify the author/publisher of the website safely and determine whether they are experts in their field?
Is the website up-to-date or is it regularly brought up to date?
In the event that you are searching for expert information, is the text written in a professional style and are the basic rules of citation complied with?