REACT!

(R) is for relevance. Any time you are searching for a website to use as a resource, you much make sure that the website's content is relevant to the topic on which you are writing about and or researching. For example, you wouldn't want to site a website about unicorns when your research topic is the life and history of Mark Twain. That website could be the very best and most reliable website for unicorn information but it will serve you useless in your quest to find Mark Twain related information.
(E) is for experience. When considering a website to use as a source, the experience of the author is an important piece of information to think about. People with experience in the field of which is being studied most often write the best and most accurate information. That isn't always the case but more times than not, it is. I mean, you wouldn't want to site a website in which Mark Twain wrote about unicorns. Honestly, what does he know about unicorns?... Or websites?
(A) is for audience. The audience to which the website is geared is very important. You wouldn't want to use a website that is very obviously meant for children with information about unicorns when your research topic is equistrian history.
(C) is for currency. It is very important for a websites information to be up to date. If you use a website with out of date information, it could very well turn into incorrect information. This is especially true when writing about scientific information.
(T) is for trustworthy. Being able to trust that the website and it's information are completely and absolutely true, is one of, if not the most important aspect of searching for a website to use as a resource.