It is an awesome privilege and responsibility to teach the Word of God, and to hold out the gospel to men and women bound for heaven or hell. Week by week the Word of God preached awakens the dead and builds up the living. It accomplishes what God has sent it for. It brings life to some the stench of death to others.
A few years back I wrote a chapter on preaching in Keeping Your Balance: Approaching Theological and Religious Studies (Apollos, 2001) available here or here.
The chapter, "God, Theology & the Pulpit: Perspectives on Preaching," is available as a pdf file here.