A manual for writers of research papers, theses, and dissertations, 7th edition - Kate L. Turabian 2007

Check your paragraphs
Revising your draft
Part I. Research and writing: from planning to production

Each paragraph should be relevant to the point of its section. And like sections, each paragraph should have a sentence or two introducing it, usually stating its point and including the key concepts that the rest of the paragraph develops. If the opening sentences of a paragraph don't state its point, then its last one must. Order your sentences by some principle and make them relevant to the point of the paragraph (for principles of order, see 6.2.5).

Avoid strings of short paragraphs (fewer than five lines) or very long ones (for most fields, more than half a page). Reserve the use of two- or three-sentence paragraphs for lists, transitions, introductions and conclusions to sections, and statements that you want to emphasize. (We use short paragraphs here so that readers can more easily skim, rarely a consideration in report writing.)