The financial statements section should show the way things are now if you have an existing business, as well as a forward look at your checking account, or projected income statement. The only way a start_up company can provide an income statement and balance sheet is by projecting these figures based upon well defined assumptions. Both start_ups and existing businesses should include a statement of owner's equity.
An income statement shows revenues minus expenses, in order to calculate net income or net loss. Start_ups should project these expected results for the first twelve months of business, then quarterly for the next two years. A list of a company's assets (what you own), liabilities (what you owe), and net worth (assets minus liabilities) is called a balance sheet. The statement of owner's equity shows the owner's initial investment, additional investments, and retained earnings, minus owner withdrawals.
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.
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.