Why do you need citations, anyway?
When you write a paper, you need to let the reader know where you got your information. That's why you provide citations - so your reader can find the material you reference.
All disciplines use a different citation style. Here's a handout on how they differ.
English classes here use MLA, but other classes might use something different. Remember - check with your teacher about which format is appropriate to your assignment.
Mr. Mailloux has created a helpful Google Doc that explains how to cite MLA style.
Another option is to use EasyBib if you are typing in a Google Doc. Ask your teacher or Mr. Keniston, the librarian, for help with citations or bibliographies.