Just tell your story, and tell the truth.
If they're going to decide against you because you're new in business, that's disappointing, but you can't get around it because the truth will come out. So tell the truth, but then go on to why doing business with you is a good idea.
And if the college doesn't want you because your business doesn't have enough history, at least this standard proposal will be a good exercise. You'll be able to use most of it again.
Tim Berry is the chairman of Eugene, Ore.-Palo Alto Software, which produces business-planning software. He founded Bplans.com and wrote The Plan-As-You-Go Business Plan, published by Entrepreneur Press. Berry is also a co-founder of HavePresence.com, a leader in a local angel-investment group and a judge of international business-plan competitions.