Entrepreneur known unkowns

I'm looking to start taking a few project ideas I've had over the past year and turn one of them into a venture. The goal is to build something I can independently run without a need for funding or outsourcing.

Where I've come up against it are a number of areas within which I do not have experience, and would appreciate any expertise and guidance.

This question is an example of my known unknowns. References to further reading and/or research topics to explore are embraced.

a. How do I test the idea itself. I have thoughts around publishing and sending out surveys, however there exists no tractable investment in the response.

b. What are the mechanics required in building a plan and for what horizon should I plan to. What considerations tend to be overlooked.

c. Experiences. If you have a personal experience with attempting to turn an idea into a small venture feel free to share what you've learned, especially if you have some hindsight into things you would or would not have done differently.