First.. Let's assume you have enough money to get by for at least 6 months. And provide for anyone in your care. Including health insurance for emergencies. If you don't have money saved up, well, I'd try to get your day job back or something else, because you could be setting yourself and your family up for catastrophe.
That said, the first thing you need to do is to get your ideas down in writing somehow. Take a day or two if necessary. It's really important. Don't just "start coding" like other people are suggesting. Get organized first. If this idea was so good that you quit your day job, you should have no trouble writing down a few pages about what you're trying to accomplish. Call it a "business plan", or not, at this stage it doesn't matter. But at least write down what you want to do, who will buy it and why, and who your competitors are.
I started to write a bunch of stuff about how to plan out your business, and then I realized that it would be easier for you to just get Four Steps to the Ephiphany by Steve Blank - it's full of worksheets that will help guide you through these early stages.
It sounds like you might need to meet some technical people to help you build your idea. You can meet them here on Hacker News, but it's far better to go to meetups in your area and meet real developers in person. The best developers will want to take some ownership in this part of the business, rather than just being told what to build.
Try to build relationships with people and tell them about your idea. If it's in a space that they're interested in, you'll find people who want to work with you, and at this stage it will be helpful to be able to bounce ideas off of others. Seek out the kinds of people who will tell you what's wrong with your idea or poke holes in it.
Hope this was helpful, and good luck!