Minna no Nihongo
Four volumes and 74 lessons, from beginner to intermediate.
How the volumes fit together
Beginner 1 starts with introductions and basic sentence patterns. Beginner 2 extends them to more everyday situations. Intermediate 1 and 2 add longer texts, conversations, listening and retelling practice. If you already use a volume, open it directly. A useful lesson sequence is text, audio, exercises, then answers and vocabulary.
The reader controls follow your interface language. Textbook pages and audio stay in their original form; vocabulary meanings and study guides retain their original Simplified Chinese.