Wikipedia provides users with lots of information about itself! See the following topics addressed in Wikipedia.
A good article in Wikipedia is just the beginning! A well researched article will provide you with a list of references at the end that you can follow up on to verify the information and research further. For example,
References From the Roe vs Wade (landmark US Supreme Court ruling on abortion) article in Wikipedia:
A well-researched article will have references from a wide variety of sources and represent different points of view. Remember, you should evaluate each of the references as well. Don't just assume everything quoted in Wikipedia is reliable and accurate.