Open your paragraph with a clear topic sentence. This sentence will introduce your reader to the next topic you will discuss and add structure to your writing. For example:
"Many studies suggest that the ocean's fish population has changed drastically in the last twenty years."
Include specific information about the topic in the middle of your paragraph. Be sure to use the middle of the paragraph to introduce your own conclusions, as well as introducing some information from reputable sources. Usually, a paragraph would be constructed with the last sentence serving as your overall observations, so include these observations throughout the paragraph.
Cite the information in the last sentence. Carefully plan what quotation, information or fact you would like to cite at the end of the paragraph. Perhaps it will be a definitive statistic, or a study's overall conclusion. Utilize the citation format sanctioned by your discipline. Anthropologists use AAA style; the discipline of psychology uses APA style; and historians use the Chicago Manual of Style. AAA and APA style use in-text parenthetical citations. Place the citation at the end of the sentence using the last name of the author and a specific page, if available. The Chicago Manual of Style uses footnotes, with a number next to the end of the sentence which corresponds to a complete citation entry at the bottom of the page. Tie this last citation into the body of the paragraph by introducing the cited information with your own conclusions or emphasis.