Start by writing a description of your business, including what stage of development it is currently in (conception, start_up, first year, mature, exit) and your plans for growth. Discuss the nature of your business, the main products and services you offer, the market for your products and services, and how and by whom the business is operated.
The risk management plan needs to be fleshed out in the organizational section as well, including your risk strategy, the different types of insurance required, your contingency plans, and problem_solving protocols. What will you do if a natural disaster ruins part of your inventory? How will you handle the sudden illness or long_term absence of a key manager? What happens if you are unable to finish a project on schedule? What are some early warning signs to watch for?
Personnel: The success of any company depends on their ability to recruit, train and retain quality employees. The amount of emphasis in your plan for this section will depend on the number and type of employees required.
Do not try to write your business plan in one sitting. As I mentioned in the beginning, for a traditional brick and mortar business, it could take in excess of 100 hours to compile all of the information needed into a comprehensive but yet understandable document. For online businesses, probably not that long. But your final product should be well thought out, well documented and easily understandable.