Sean Wise has a good story in the Globe and Mail about how important Boards of Directors can be for a small company. It is worth the read but here is an important excerpt:

On a five person Board of Directors, post outside investment, the following structure is recommended:

The CEO;

Another key member of Management i.e. possibly the CTO or the VP of Sales;

A representative of the foundering shareholders or the early investors;

A representative of shareholders from the last round of investment; and

An independent Chairperson