Ask HN: Pitching an iOS/iPhone App Idea

I have an idea for an app that is solid. I have no doubt it will be viral, it's not be done now.

I have no experience with making an app but I do have a decent business background.

1) Investors keep telling me that angel investors & VCs don't mess with NDA regularly, they just want me to spit out my idea. How true is this?

2) Does anyone have an example of a business plan or investor presentation for an app?

3) What is a fair stake? No doubt this thing will sell 1mm+ units in 90 days or less @1.99... If someone buys in at 50k, what is a % that is fair? 100k?

Thanks guys, I'm sure I sound like a noob but I am.