I just listened to a great 2-part lecture by R.C. Sproul about God's Will and Your Vocation. It's really worth the 45 minutes.
So many Christians (at least in the evangelical circles) are so focused on finding God's will for their lives. Usually, the question they're really asking is, "What should I be when I grow up?" Sproul answers the question with a sound biblical approach, showing us how we can honor God in our vocation while using your own personal talents.
Have a listen!
This lecture appeared on Renewing Your Mind, R.C. Sproul's daily radio broadcast. You should think about subscribing to their podcast.