I love what Steve Covey says about this in The 7 Habits of Highly Effective People. Covey states: "If you know the failure paths of the job, identify them. Be honest and open - tell a person where the quicksand is and where the wild animals are. You don't want them to have to reinvent the wheel every day. Let people learn from your mistakes or the mistakes with others. Point out the potential failure paths, what not to do, but don't tell them what to do."