How do I know if this idea is good enough?

I only ever work on something I would personally want to use.

There is no guarantee that anything you make will take off but chances are you're not alone and some people are enough like you to buy your product.

Unless you're Homer Simpson and are thinking of making a new car that is.

We did an MVP as well, but we also learned a lot from a quick 5 questions survey. We got 60 answers from our target market, identified and confirmed pain points and got our initial beta testers this way. We just asked people to fill it out and spread the word on FB and Twitter.

I have the same problem, I have shit tons of ideas yet I don't know how to begin. I am a programmer btw.

All I know is that my preferred domain is skill acquisition / coaching / e-learning / personal development.

Free ideas 'r' us: http://ideashower.posterous.com

You did some research and concluded that your idea is promising. But do you trust your idea? If so, build your product, and stick with it, and push it for as long as you can. It may not take off right away, so you need to have a great deal of optimism to keep things moving. Maybe your product will eventually become successful, or maybe it will bring you other profitable opportunities. So, do you trust your idea, or you need others to convince you to trust it? My point is that if you don't fully believe in the potential of your product or idea you're gonna have a hard time.

Find one paying customer.

I was facing the same question with my website. I decided the best way is to put a minimum viable product out there with minimum investment to see if it is getting any traction.

people don't know what they want until you give it to them.