External stake-holders of non-profits include donors and the clients of the non-profit's services. For government agencies, external stakeholders include tax-payers, higher-level government agencies, and international lending bodies such as the International Monetary Fund, the World Bank, various economic agencies of the United Nations, and development banks.
Once you have done all this you should have a complete and detailed professional business plan. The most important thing to remember when developing the plan is to see it as a living document and include specifics regarding dates and specific responsibilities. Your plan will need constant reviews and updates and things change so expect it to be a work in process for a good stretch of time. It will all be worth it in the end, a well-written plan will help ensure that the business is fully focused on what is required to achieve the company's goal.
The market potential for your service or product-You need to convince your customers and employees for your products and services you are offering and hence you have to find out the market which needs that product or service.
A brief account of how the company began- You should mention in your business plan the history behind the formation of you company and the background of the founders and directors.