I mentioned the financial aspect of a plan earlier, so let me add this. Another fact about financials to consider: not all business activities are about making money. Point being, in most enterprises financial considerations are centric to the document. But there are some other considerations. For example, a few years ago I wrote a plan for a new subsidiary that was focused on developing an inventory of patents. The potential financial returns were years into the future. Those patents may or may not ever have commercial value. Another example is a non_profit enterprise that has need for a complete roadmap for growing their profile in a market, of which a marketing plan would be the centerpiece.
Where can you find samples of a business plan for a small business? If you go into any of the search engines such as Google or Bing and type in "samples of a business plans for a small business" you will find websites with this information. This is why it is important that a small business should have a business plan. If you look at those small businesses that are successful, you will find that most of them all started with and have a plan for their business.