It's a must read - God at Work: Your Christian Vocation in All of Life by Gene Edward Veith, Jr. The first time I read it was for a class I audited with Britt at seminary. I think I read it in a day. It's 164 pages and not a difficult book to work through. But every chapter is worth reading. He discusses what the purpose of vocation is and how to find your vocation, but he also discusses different types of "work" - our roles in the family, our society, and the church.
I would recommend this book to people of all ages, even those who have found what they love to do. It just gives you a better perspective on what the goal is of working - glorifying God.