A search on a word etymology (which I'll finish next time I lay hands on the OED) led me to Answers.com. Interestingly, I discovered that Answers.com also gives proper MLA, Chicago, and APA citations at the bottoms of their entries. I've tried several, and all came out accurately, so it seems pretty reliable.
As an example, let's look at the entry for "Beowulf." Scroll to the bottom and you'll see a box with "Copyrights" and little bubbles that say "Cite." If you click on one of the bubbles, such as the one for "Literature Information about Beowulf," you'll come to this page. Note also that you can change the citation style ... and it even reminds you to use a hanging indent. Nice!
If I were a freshman, and needed to cite some general information, I'd probably use this site just to be sure I had the citation correct. It probably doesn't have the ethos for anything beyond basic, general info, but at least it offers a good model.