I come from a not for profit background so most of the "fundraising" I do is somewhat different than what you are talking about. That being said I would recommend reading Jerold Panas's book "Asking." He is talking about charitable fundraising but the book is short and it touches upon key motivators which can be adapted to a business environment where you are really looking for investment. The big key is to get them talking. People who are being asked for money, think that they are pretty smart and so if you talk at them they will phase you out. If you go seeking advice you can draw them into the idea and they will want to be a part of the company.