There are differences in form between literary works--novels, short stories, poetry, and drama--and classic/standard non-fiction, sure, but the methodology of approach and comprehension--the reader's task--continues: to ascertain and analyze the facts and the visible signs of argument, emotion, and ethics.
Analysis:
identifying the parts and understanding the relationship between the parts and their relationship to the whole.
Understanding complexity (and not merely complication).
Answering the question, over and over again, for each part:
How does X contribute?
Creating--or encouraging--readers.
Enabling--and enobling--students?
What else?