Some key differences to consider:
- Coaching is based most often on a monthly retainer. Mentoring can be as well, but is usually offered without a fee, often based on a personal request or referral.
- Coaches rarely give advice, coming from the perspective that the client has the answers within. Empowering yes, but there are times when you just want someone to give you a straight answer or share their experience. Mentors (and consultants) provide this more naturally.

I've worked with entrepreneurs who've had both, and I've done so myself. If you're looking for personal development within your business, I'd lean towards coaching. If you're more after advice and experience, I'd look for a mentor. Both are helpful and can make the world of difference in the right circumstances.