I do not have reservations about using Wikipedia for research purposes.  For class work, I suggest using articles that have citations in them and researching those sources as well. This way, the value of your sources are not undercut by using an open source of information such as Wikipedia.  The previous Wikipedia search engine stopped working, so I switched it for a German version.  Just about every article is available in every language and you can switch between languages easy enough that I felt this wouldn't present any major problem for students.

This site is a dandy translation page.  You can't translate whole documents, but you can find the meaning, conjugation, and different uses of the words in German and other languages.  You also can find phrases, sayings, and idiomatic expressions, which may not otherwise find in most textbooks.