A major informational site is wikipedia.org, the online encyclopedia. It is unique, because it allows visitors to contribute and edit articles. Now your small business may not want such a comprehensive site, but if you have information to share of sell, an informational website would fill the bill.
Suppose you have a landscaping business. You could create a website that lists plants wit their definitions and planting and caring instructions. This would be helpful to people, and you would use it to lead people to your nursery.