I am the mentor on FRC 2789 that led the sub-team that produced our business plan. Our business plan was heavily influenced by the following book:
Business Model Generation by Alex Osterwalder & Yves Pigneur
You can find the book and related materials at
http://alexosterwalder.com/
Prior to writing our business plan, we created a business canvas that described our current business model. Doing this helped us to clarify what value we brought to the communities we serve and helped us to compile and organize all the partners and resources our team needed to gather in order to continue to provide our value propositions. We learned a lot(!) from this book.