Questions about working with/becoming a mentor

I work at Think IT, a professional networking group for Minneapolis-area IT professionals and we have been working on a mentoring program the past few months. I wanted to ask the spiceworks community a couple questions:

1. What do you look for in a mentor? Is it someone with technical skills you want to attain? Is it just someone with more experience in your field? Is it someone who's moved up the ranks in his/her IT department? What's your ideal mentor like?

2. If you've been a mentor what is the biggest reason you became one? What have you gained from your experience as a mentor? Was there anything that surprised you?

Thanks!