I've worked on the subject of entrepreneurial mentoring since 2007 and I have summarized some key points in this downloadable pdf doc:
These should answer your questions about overall mentoring relationship but concretely the key on your side is:
- openness (which is ok given the required matching condition of no potential conflict of interest) to share and to listen
- preparation - ensure you are ready and have questions or things to put on the table before each meeting with your mentor
- autonomy of decision (it is your business and you can choose not to follow mentor's advice)
Contrary to Ian's response a mentor is not paid / compensated it is a voluntary activity (pro bono) but maybe Ian was talking about a coach who is paid as it is a professional activity. A mentor in your case should be an experienced entrepreneur who is willing to support your thinking about your business for at least 6 months seeing him/her once a month. Formal mentoring programs are well developed around the world these days.
Best of luck