how-to
adjective [ before noun ] uk/ˌhaʊˈtuː/ us/ˌhaʊˈtuː/
（书籍、录像等）入门的，提供指南的
A how-to book, video, or other product provides advice on a particular activity.
How-to books on dieting are often at the top of the bestseller lists. 减肥类书籍常常位于畅销书排行榜榜首。