When you're looking for help on the World Wide Web, it is very tempting to seek out popular resources that everyone else recommends. The problem with popular resources is that they are usually not very reliable. Take Wikipedia, for example. I wouldn't trust Wikipedia's content if my life depended on it. People are constantly zapping Wiki articles, trying to add their own spin. Wikipedia's content also consists mostly of "original research", which is ironic because it's against their policy to include "original research".
Good resources are usually maintained by professional organizations that have to observe accountability. Wikipedia, for example, is accountable to no one. But a site like Dictionary.Com is accountable because people compete with it. The business of operating dictionaries is very competitive and levels of accountability and authority have been clearly established for over a century. Encyclopedic resources, even resources as well designed as Britannica, are not considered to be as reliable in academic research as original research published in journals. But at least Britannica observes a standard of editorial professionalism that is completely lacking in Wikipedia.
Another good resource is Columbia Encyclopedia because they, like Britannica, implement professional editorial standards of control. If you have to trust an online resource, then Britannica and Bartleby are better sources of information than Wikipedia. For that matter, Encarta by Microsoft is another good resource. While not as robust as Columbia Encyclopedia or Britannica, Encarts still uphelds a standard of editorial responsibility that is simply lacking at Wikipedia.
And if you are looking for dictionaries, then Merriam Webster's Dictionary is another reliable resource, as is Cambridge Dictionaries Online. Just because Wikipedia is more popular than these other sites does not mean it is better. That popularity only underscores just how far ignorance can lead people astray. Stay as far away from Wikipedia as you can, because you have no way of knowing how accurate the information there may be.