Neither of these is going to tell you what to do. They'll get you thinking along the right lines, ask you the right questions, and help you with the mechanics. Every business is different, but the process of writing a business plan is useful for any business.
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.