What you need to do next is to take your idea through an opportunity evaluation process. This is where you can tweak, improve and plan the BUSINESS side of it (as opposed to the product.)
Things you should look at include being really specific about who your customers are, how you are going to generate revenue, what business model you will use, how you can prevent others copying you (creating a sustainable competitive advantage), what resources you need and looking at the risks and how you can mitigate them. And of course do some financial projections.
It is also important to test your idea in the market.
The mind map in this post shows the main issues you need to tackle. And it is really important to validate all your planning and thinking by getting out there and talking to people who know the market and also by doing secondary research.
Basically the end result you want is to feel confident that there is a business opportunity there. You also want to adjust your initial idea if you find that it's not quite what the market wants or if it doesn't seem like it's going to be profitable.
Once you've been through the process you will have a really deep knowledge of your business and industry and have the basis of a great business plan.
It sounds like a lot of work, but I train a lot of people in this process and they generally feel it's really worth doing. The pay off in improving your idea and identifying the key issues for your business is huge! And it can also save you a lot of money if your idea is not profitable - either by changing it to improve it or ditching it and moving on to something else.
Good luck! and Let the Adventure begin!