Your mentor – it could be somebody who has done something similar to you i.e. gone into the same line of business. Therefore they know the world you are going into quite well, and can give you a great deal of sector knowledge; they may also have a useful rolodex of contacts to contribute.
It could be somebody who has successfully built a business of a different type or in a different sector; he or she can therefore anticipate what is going to happen next, and consequently help you to prepare for that as you go through the “growing pains” of developing a successful business.
“Find an honest mentor who you can talk to. Not a friend who will tell you what you want to hear, but someone that will – in a positive and constructive way – challenge and mentor you through the journey”. – Mike Teasdale
Finally it could be somebody who has a skill you don’t have.
I did a lot of work down in Brighton with early stage technology businesses, where quite often there was one founder. These people would be very technically competent, whatever their area of IT expertise was, but quite often at the expense of other skills.
One option for them was to identify a mentor who was strong on marketing and sales. Typically they had a product or service that was advanced and innovative, but they did not know how to commercialise it.
So, having a mentor who could help them figure out how they could take their offering to market and maximise it made a lot of sense.
It will be a different answer for all of you. If there is nobody that springs to mind, just keep your antennae up as you come across people and figure out who might be able to do that job for you.
As I said, I have seen a direct correlation between people who take this step and people who make the transition successfully.