The language of business is financial statements. Income and expense, assets and liabilities all of these are critical in describing your business. But just as important are the unit economics. This is basic stuff, but you would be surprised at the lack of this kind of info in most business plans. Similarly, focus on cash flow and profits.
Cash flow is the lifeblood of a business.
If you don't have cash coming in the door in a reasonably steady stream, then you are going to be in a world of trouble. Cash flow is a good example of the concept of timing being everything. The money has to be there when you need it. What you DO with it is usually negotiable. But without the cash flow, you have nothing to do, nothing to talk about.