Web Sites--do not assume that you can tell if a site is legitimate from the address. The site www.martinlutherking. org is not a site for information about a civil rights leader. It is a site run by white supremacitists. Educational sites use the .edu ending for students as well as faculty so you may end up quoting a fellow college student's paper rather than something produced by a professor.
Wikipedia -- A wiki allows different people (not always experts) to contrubute to a web site. Because the information can change from moment to moment, depending on opinion or humor, Wikipedia is generally NOT considered a suitable resource for your papers.
Google is a search engine not a fact checker. If you Google “cigarettes are good for you”, Google will find web sites that agree with that statement. Try Google Scholar which may find more scholarly resources for your paper. If you can't get the full text from them, use the abstract or citation and go back to the research databases to see if you can access it for free.
Advertising -- Search engines often put their sponsored sites first. Make sure no one is trying to sell you something when you’re asking for information. Information may be biased toward their product.
Internet search engines like Google, Bing, Yahoo and DuckDuckGo are programs that search documents (such as websites) for key terms.
Google tracks users searches to generate specialized results. This can prevent a user from finding the most relevant information.
DuckDuckGo allows user privacy and has less advertisements, which can mean less distracting sponsored webpages.