Mentoring is by far one of the best tools parents have to positively influence our children and grandchildren. Mentoring requires two important aspects - Modeling and Teaching.In my opinion you cannot do one without the other. You can preach relentlessly to your children but unless you model, the message will not be received. However, you can also model relentlessly to your children but unless you teach them, the message will be incomplete. 
Mentoring our children serves to nourish and enrich their lives by showing them the substance of our beliefs, morals and values. A mentor can also come in other forms besides a parent - a grandparent, a coach, a pastor or any older figure that exhibits and models the desired traits to be learned and attained.
Mentors are important because human beings tend to become like those they associate with and associating with mentors who embody positive character traits, encourages children to do their best while providing a directional compass in life.
The true magic of the mentoring process is that it offers children the opportunity to turn their potential into reality, their dreams into destiny and like the magic of compound interest, small deposits by a mentor over a long period of time can equal unmeasurable results and fruits in a child's life.
However, to mentor someone effectively, we must first be invited to mentor them. And once invited, we must seek to understand them. This means listening intently to them, discovering what their hopes, dreams, challenges, aspirations, and fears are but more than that you must be able to empathize with them and then and only then offer guidance. Sometimes, mentoring is not talking at all but simply listening and being present.
I can think of no better illustration of the mentoring process then the movie The Blind Side. Whether you have previously seen this movie or not, I challenge you to watch this movie this week and look for key examples of the embodiment and key characteristics of the mentorship process.