When choosing your board members, always remember the bus number. The bus number is a term that I learned in IT - it is the number of people on a project that can be hit by a bus without the project being impacted. Naturally, this number should be as large as possible.
One issue with many small nonprofits is the bus number is 1 - the founder. If something happens to the founder, the organization collapses.
So, when choosing your board, remember that the board manages the nonprofit - the board does not work for you. If you want to be the Executive Director, you work for the board. So, the board must be intimately involved in all decisions about the organization. The board approves budgets. The board approves programs (every grant application I have seen asks if there is board support.)
If the board does not manage the nonprofit and the founder does all the work, burnout is a real concern.
If the board is going to manage the nonprofit, then the board needs some basic business knowledge. Then, there are some other suggestions for the "perfect" board member:
Believe in the organization
Donate to the organization
Manage the organization
Market the organization (to their family, friends and co-workers)
Questions to ask your board:
What is our mission?
What is our budget?
How long does it take to get a grant?
Do you have an elevator speech?
The board will (should) manage your nonprofit. They should share your vision. They should believe in the mission. They should be able to take over if you wander off.