Jean Chatzky has been working with viewers of NBC’s Today show for a series on how to get out of debt once and for all. Her method, both on TV and in this book, is simple yet powerful: the key is saving just $10 a day that you currently waste. It doesn’t sound like much—a movie ticket or lunch for two at McDonald’s— but $10 really can take you from debt to wealth in just a few years. And because it doesn’t feel like an impossible goal, people are more likely to stick with Chatzky’s plan than...