First of all, please don't take what I am about to say as discouragement. The 'idea' is the absolute first step, BUT there is a little bit more. :)
Now that you have the idea, the very first next step is entirely on you! You have to make some hard decisions, about your desires, your goals, how you will incorporate your business into family, friends, and all of the other things you like to do. If you want to be successful, be prepared to trade all of that, and your time.
The next phase is to start research. learn everything you can about your prospective market. Who are your customers? Where do they live? What kinds of things do they like and dislike? Get their shoe sizes if you can.
Then, math. The hard part of this step is that much of the information you will be using is 'guess work'. You can call it estimates if it makes you feel better, but it really is guessing. Try to determine from your market research if you can sell enough of your product or service, at a high enough price to scrape a little bit out for yourself, and do it in a short enough time that you won't get the car re-posessed or lose the house to the bank. Always keep in mind that you could have guessed WRONG at any point in your 'estimating' process. :)
If your numbers seem to say that you have a real shot, it's time to start looking at reality things. Place of business, licensing, insurance, labor, signage, equipment, decor, product & stocking, shipping, phones........ etc.
These will all be pretty much 'hard' numbers. People who sell things generally give you a good idea of what they want for them.
Match the hard numbers and the soft numbers. Try to decide if they still show a good enough picture that you want to proceed.
I strongly suggest you spend NO MONEY, yours or anybody else's until you've finished the above.
Funding is a good question, but it demonstrates that you probably don't have the resources put aside to cover your 'hard' costs. Your choices are going to be limited. You can 'bootstrap' your operations (95%+ of all new business starts fail in their first year - but generally NOT because they lacked the money to start.) Loans will still require you to come up with some part of the total contribution, and your 'labor-idea' doesn't generally get recognized with a dollar value by the bank. You can write up a business plan and look for private investors. You can win the lottery. Personally, bootstrapping is the one that works the best. Start small, shoestring size, plow the 'profit' back into the business over time until you reach your pre-planned 'funding level'.
Keep in mind, your time is the most important asset you will have totally under your control. You will still have to eat, keep out of the weather, and probably a few other things while you are making the business grow. Not impossible, just 'challenging'. :)
Good Luck!
Source: http://www.abusinessmentor.com