Sudden changes of subject will make readers stumble, but choosing a suitable ordering for your topics will often let you flow smoothly from one to the next. When no ordering seems to work, try breaking the text into separate sections, each on a separate subject. Within a section, paragraph breaks can be made less abrupt by anticipating the next subject at the end of one paragraph, or by referring to the previous subject in the topic sentence of the new paragraph. Paragraphing is especially important in naive-user documentation, because documentation is consulted, not read like a novel. Related information must be brought together into one paragraph or into contiguous paragraphs, so that users looking for one piece of information will see the essential related material.
Students usually write for a single audience, their teacher.
Because the teacher usually knows more than the students, the purpose of the writing is usually to impress, and not to inform. The teacher's purpose is to find out whether you learned anything, and, sometimes, whether you can articulate your thoughts clearly. Rarely is the teacher interested in the ostensible content of the paper. In this assignment, you are writing for a different audience, one presumed to know less than you. Your readers will not know all the jargon you use almost unconsciously, so you'll have to be extra careful about which words you use.