The executive summary you give to your potential investors should be two to four pages long. This list from Guy Kawasaki’s Reality Check covers the components that should be included in the executive summary and can be used as a template:
Cardis, J., et al. (2001). Venture Capital: The Definitive Guide for Entrepreneurs, Investors, and Practitioners. Toronto: John Wiley & Sons.
Kawasaki, G. (2008). Reality Check: The Irreverent Guide to Outsmarting, Outmanaging, and Outmarketing Your Competition. Toronto: Penguin Canada.