Complex sentence: Her first cook book "The Pleasures of Vegetarian Cooking" was published in 1974, and since then she has written over 100 books and in all sold more than 3 million books.
Split into simpler sentences: Her first cook book, "The Pleasures of Vegetarian Cooking", was published in 1974. Since then she has written over 100 books and sold more than 3 million books.