If you're unsure about creating your own template, a client of mine recently used LivePlan.com. I reviewed their business plan (as an authorized user) and found it simple to follow and to edit. And at a fairly low cost.
You'll want to create a clear outline that includes:
Executive Summary (who you are, what you do, what you bring to the table)
Company Overview (management, personnel, mission statement)
Strategy and Implementation (marketing strategy, your competition, and not just that you're going to increase revenue, but how you're going to do so)
Financial Plan (the most important, which should include a revenue and expense forecast for at least 3 years but 5 would be better)
So start thinking ahead so that you're not left feeling like this!