I have been writing since I was a small boy. Short stories, a novel, even, at age 12, and numerous poems and written paraphernalia grace notebooks all through the house. I have written 5 basketball books - 4 of them are textbook in nature. I always learn more about the game when I write about it. Now, I'm not advocating that coaches run right out and start writing books, but a good place to begin is with an article.
Books can come later.
I'll list here several helpful hints in putting together an article for a basketball publication. I first heard that old axiom from the late Truman Capote, the much-heralded novelist of the 1960's. Capote was on the Tonight Show and he was talking about his craft. And write voraciously. I have always been a firm believer that writers should write regularly, not occasionally, but for the average writer, knowing one's subject is paramount to expressing it properly.