For great advice on finding a mentor, read this.
In short, it works like as follows:
The best mentors have no agenda. They care for you, they advise you with only your own interests at heart.
Parents, uncles, aunts, teachers, bosses.
To find mentors outside of this circle, do this:
Reach out to as many role models as you can. Write letters to break the seal. Ask for intro’s from mutual acquaintances.
Engage, but don’t irritate. Flattery is irritating.
Provide some value in return. Even if that value is simply a free book every visit.
Finding a mentor is like finding love. It’s a numbers game. You have to knock on lots of doors and be rejected lots of times.
Don’t give up.