Wikipedia?
You already know how helpful it is to get some background information on your research topics. Wikipedia is often the default because it's so easy to find an entry and the entries can sometimes be helpful.
That said, the quality and reliability of Wikipedia entries are not something you can count on. A Wikipedia entry is only as good as they sources it cites. You should not cite Wikipedia, but you can follow the source notes.
For your research papers, we suggest that you browse or search some of the library's online subject encyclopedias. Admittedly, they are not as easy to search, but the quality of the entries is often worth the effort. In addition, the entries are signed by the author and include the citation.