Because anyone can add information to the web, be skeptical when evaluating any information source. There is no universal symbol to designate a quality web page, but here are things you can look for to help you determine if a web page is appropriate or not:
Point of View or Bias
There's nothing wrong with a source having a point of view, but you need to be aware of it so you can investigate the other sides. Example: Information on gun control from the National Rifle Association.
Think about your topic and how important recent information is to it. For an art history project , it probably isn't very important. For a paper on genetic engineering, it is very important.
This is the ultimate point. But you may not know enough about a topic to judge. Look for solid evidence, such as research studies and statistics. Is there a bibliography or reference to other sources the author used? These indicate the information is based on research rather than just opinion.