For beginners of German, the most suitable books should be introductory language books such as "German Elementary Course" or "Basic Course of German grammar". These books provide basic knowledge of the German language, including grammar, vocabulary, pronunciation, etc., which helps beginners quickly master the basic elements of the German language. In addition, beginners can also improve their language skills by reading German articles or books. You can choose some simple articles or books such as children's books, novels or simple literary masterpieces. These articles or books cover common German vocabulary and grammar structures to help beginners better understand the German language. In short, for beginners of German, language learning introductory books are the most suitable choice. Through reading books, you can improve your language level and gradually expand your vocabulary and grammar knowledge.