Every year a new book comes along that is truly worth taking the time to read — and more than once. This year’s outstanding book is the just-published “How to Retire: 20 Lessons for A Happy, Successful and Wealthy Retirement” by Morningstar’s director of personal finance, Christine Benz. While most of us view the words “retirement planning” as an exercise in deciding whether we have enough money to quit work, Benz has taken the concept of planning for retirement to a broader level.