The three basic actions for growing a business in any economic climate are: improve efficiency (maintain output while reducing inputs, such as time and money); increase volume (produce more in order to spread fixed costs); reorganize the business (change goals, methods and/or philosophy). If you plan to implement one of these, you may as well plan to implement them all. By focusing on one of the above strategies, you will find a ripple effect that causes a need to address the others. This is a good thing.
Business Description: After the executive summary, you need to write a short description of the business you are going into. You need to give a general description of the industry your business belongs to. You will write about your company's mission statement, goals and objectives, business philosophy, as well as its legal form of ownership (sole proprietor, corporation, LLC, etc.).
No matter the economic slump, increasing profits is typically the number one goal of any business. To ensure profitability, a company must demonstrate a competitive advantage over others in its industry, either by cost leadership (same product as competitors, lower price), differentiation (same price, better services), or focusing on an exclusive segment of the market (niche). For long term maintenance of competitive advantage, a firm must ensure that its methods cannot be duplicated or imitated. This requires constant analysis and regular reinvention of competitive strategies.
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.