1) They don't know if their idea is ready
2) They want the angel to sign an NDA before they talk
Both of these concerns are understandable and very common, but neither is a good reason not to start talking to angels.
Idea is not ready -- It's never really too early to get angels involved in your project. Start taking them out to lunch as soon as you can. Ask them for feedback and then apply it. Show them that you are sharp enough to seek out good advice from smart people, and tough enough to execute. The more involved an angel is in the development and birth of your business, the more likely he/she is to get financially involved later on.
NDA = Prenumptial on the first date -- Asking an angel investor to sign an NDA before you speak with him/her is like bringing up a prenumtial agreement on a first date: Way too much commitment way too early. An NDA is a liability that most angel investors are not willing to take on until much later in the due diligence process, if at all. Entrepreneurs, please heed my warning -- asking for an NDA before the first pitch is suicide 99% of the time. It gives investors the impression that you are either stupid or naive -- or both. Neither quality is likely to encourage an investor to take the plunge with your company.
