Small Business Management - Business Plan

Dear Brain Mass, I am recently working on a project on small business management, and I have to work on a scenario where my wife and I are in a small business and we have to work around some problems that are common when dealing with a small business.

My wife and I, both in their 20s, worked for one of the largest package delivery services in the world, but our jobs on the package-sorting line were just that-jobs. We wanted more from our work than our current jobs could offer. That's what led us to buy a local auto detailing business, Precision Auto Detailing. We could work their regular shifts at the delivery service from 6 p.m. to 10 p.m. and could devote the early part of the day to running our own company. We invested just $6,000 in the detailing business, which bought us some tools and equipment (most of it rather old), a lease on a building in a high-traffic location, and a small base of established customers, some of whom were local car dealers.

My wife and I kept both of the part-time employees the previous owner had hired and began making sales calls on other car dealers in the area to try to earn our business. Precision Auto Detailing offered pick-up and delivery of the cars we cleaned, and my wife and I always inspected the cars before they were returned to their owners. Our strategy was to provide top quality service and convenience at a fair price. Precision's prices ranged from $100 for the basic detail job to $250 for the top-of-the-line specialty cleaning, which resembled an auto restoration job.

Within eight months, Precision's sales were growing rapidly due largely to the personal selling efforts of its new owners and to the quality of the work the company provided its customers. We knew we needed to purchase some new detailing equipment, and after several customer inquiries, we were considering buying the equipment to offer a spray-on truck bed liner service. The bed-liner equipment would cost about $30,000 initially, but retail prices to customers for the service would start at $350 and go up, depending upon the size of the truck and the options selected. The business has been profitable since we bought it, and we have been plowing almost all of the profits back into the company. Our retained earnings are just not yet enough to sustain the rapid growth the company is experiencing.

QUESTIONS:

Having this situation in mind, I will have to have a business plan which I have no experience on that, which lead me to the following questions.

Why would we need a business plan?
What outline of element would you recommend us to include in our business plan?
What do bankers, other lenders, or investors want to see in a business plan?
What advice would you offer us when we are ready to present our business plan to a banker?

Thanks for your help.