Wikipedia.org is often berated by college professors as an unacceptable source in undergraduate papers. I, however, have no qualms whatsoever about college students using Wikipedia as a source in their papers.
It must be assumed, with respect to almost any topic a human person can give name to, that a Wikipedia article on the subject represents the bare minimum of what an educated person ought to know of the subject. In case after case, I have found Wikipedia informative — and profligately so in some subject areas. My own experience with Wikipedia suggests that it always surpasses the print encyclopedias in breadth, and that it quite often surpasses them in depth as well.
Wikipedia frequently serves as a repository of reference terminology and raw data, and usually offers a decent entry level discussion of the topics it treats; and what topic is not treated in Wikipedia? If there is an admixture of ineptitude or bias (other than the inevitable systemic and endemic ones) in Wikipedia articles, it can usually be detected fairly easily and corrected for by further investigation.
What I tell students is Wikipedia can profitably serve as a starting point for research, especially if it is used in conjunction with other, more traditional encyclopedic sources. But I also teach that further investigation is always mandatory. I may even encourage students to read multiple Wikipedia articles on various aspects of a topic before beginning their investigation in earnest. I thereafter direct them to the more advanced sources I typically want to see being used. In other words, there’s nothing wrong with Wikipedia — and there’s a lot about it that’s right! — but woe unto that student who allows research to start and end at Wikipedia.
Finally it should not have to be said, yet it must be said, so I will say it: Wikipedia, like any source, must be used ethically and responsibly. One must not cut and paste from Wikipedia (or any source). One cannot cite, repeat or even imitate phrases or passages from Wikipedia without properly marking them as quotations. Whether it is the lowly Wikipedia or the most respected scholarly tome, you have to cite the sources you consult in footnotes and bibliography whenever and wherever such sources contribute to your presentation of a topic. But y’all knew that already.