Here is a light-hearted look at how not to mentor introduced to me by David Clutterbuck at a mentoring lunch in Birmingham!
Start from the point of view that you - from your vast experience and broader perspective - know better than the mentee what's in his or her interest
Be determined to share your wisdom with them - whether they want it or not; remind them frequently how much they still have to learn
Decide what you and the mentee will talk about and when; change dates and themes frequently to prevent complacency sneaking in
Do most of the talking; check frequently that they are paying attention
Make sure they understand how trivial their concerns are compared to the weighty issues you have to deal with
Remind the mentee how fortunate s/he is to have your undivided attention
Neither show nor admit any personal weaknesses; expect to be their role model in all aspects of career development and personal values
Never ask them what they should expect of you - how would they know anyway?
Demonstrate how important and well connected you are by sharing confidential information they don't need (or want) to know
Discourage any signs of levity or humour - this is a serious business and should be treated as such
Take them to task when they don't follow your advice
Never, never admit that this could be a learning experience for you, too