A plot in nonfiction gives information with the goal of making a point or bringing your reader to a specific conclusion. Just as in fiction, the plot needs to have a beginning, middle and end. Give the reader a taste of what they will learn in the opening; whet their appetite so they will continue to read. Tell the reader what you want him to know and why the information is important. Then motivate him to apply the information.
Research to fill out the story or facts with details that give the reader more information on the setting, history of the character or time period. When Truman Capote wrote "In Cold Blood," he spent hours interviewing townspeople, making personal observations and reviewing official documents. The details transformed journalism into a narrative masterpiece of nonfiction.
Link the events in your story to previous or future events to show the results of the characters' actions or how specific information can produce desired results. Writing consultant Dorothy Wall uses the image of a string of pearls compared with a row of dominoes. Communicating a straightforward chronology is like a string of pearls---the information just sits there. But events that build on each other by showing cause and effect are like a row of dominoes. Each successive block is effected by the one before it. In this way, characters develop and information takes on deeper significance. The plot moves forward with energy.
Feed the reader only bits of information at first and keep them hanging at the end of a chapter, so they'll keep reading. If someone is trapped in a burning building, don't let him out until the next chapter. The tension created by "not knowing" keeps the reader interested.
Stories do not need to be chronological. Start the story with a strong, dramatic event, then move backward and fill in the details. Show how the past effected the current state of things, then move forward with the story.
Use creative imagery to frame your story. In "Building a Home With My Husband," Rachel Simon uses the tale of a home renovation to communicate lessons she learned about life and love. The progress in the building project moves the story along and introduces each new lesson or struggle.