If it's truly a great idea with a good chance of making money, then you're going to need to spend money to make money. If you don't have enough money to get it going, then you need to find someone (or many someones) who do, and convince them to invest in your idea (and they, of course, will want processes in place to make sure you are using their money in good faith). This is how the business world works in general. Yes, sometimes a few people get together with just an idea, work on it in their spare time, and eventually launch a successful business -- but that's really pretty rare, and it's hard to get to market quick that way and get noticed unless you're really, really good and/or really, really lucky.
But whichever way you go, make sure you get a good non-disclosure agreement, and have anyone who is interested in your project sign it before you start telling them all about this great idea. (And if it's truly an original idea, consider seeing if it can be patented.)