Check out the Content of the website or webpage. Is the topic covered comprehensively, partially, or is it an overview?
Is the content reasonable? Are original sources linked or cited?
Is the site useful to your purpose? No matter how good a website or how well written, if it's not relevant to the topic you are researching, it is not useful. Does the website support or refute an argument? Does it provide "wrong" informationthat can be readily challenged? Do the links work?
How is the site supported financially? Are the advertisements distinguishable from the health information?
Health On the Net Foundation (HON) promotes and guides the deployment of useful and reliable online health information, and its appropriate and efficient use. "Created in 1995, HON is a non-profit, non-governmental organization, accredited to the Economic and Social Council of the United Nations." "The HONcode certification is an ethical standard aimed at offering quality health information. It demonstrates the intent of a website to publish transparent information."