APA, MLA, or University of Chicago, whatever style you need to use, they can all be a little tricky at times. There are guides to these styles though; click on the Citation and Bibliography Styles link on the library home page.
You'll see the main styles listed there, with links under each. There will be a link to "Diane Hacker's..." site under most of them; it's an excellent link to see examples, incuding of sample papers.
It still can be a little tricky though, and if you're not sure you're welcome to ask a librarian. Just remember, we sometimes are stumped ourselves, and in the end your professor, who is grading the paper, is the best person to say which way to go.