Share results (financial and key metrics) with the company every month.
The second part of how to hire: try not to.
If it works out, you're going to be working on this for 10 years.
AirBnB happened because Brian Chesky couldn't pay his rent, but did have some space.
Good startups usually take 10 years.
If you compromise and hire someone mediocre you will always regret it.