When you are writing a paragraph and you notice that it has stretched over two or three or seven pages—the same paragraph—you need to remember how it felt to be reading one of those "classics" from the canon back in high school. Remember flipping through the pages to see if and when a particular paragraph ended? Usually, I would bet, the act of flipping through pages to find a paragraph's demise ended up with you either setting the book down or throwing it against a wall.
I'm an advocate of reader-friendly paragraphs—four, six, eight sentences that never last more than one page of typing paper—especially at the beginning of your career. Once you have become an established writer, then you can experiment with page-stretching paragraphs.