It sounds painful, but it doesn't have to be! Basically parenthetical documentation or in-text citations means that you are telling the reader where you got any and all information that did not come from inside your own head. This is more obvious when you are directly quoting from a source, but it is also needed when you have summarized or paraphrased from a source and even if you got an idea from somewhere else.

So how do you do it? As the names imply, you are going to put the information about the source in parentheses in the text of your paper as opposed to a footnote where the source information is at the bottom of the page or an endnote where it goes at the end of your paper. There are slight differences depending on which style you are using - APA or MLA.

Instructions for MLA Style (pdf)

Instructions for APA Style (pdf)