First, do a market analysis, find your competitors, describe what is the advantage of your service over others.
Rate audience of the project, consider monetization mechanisms, etc.
Then go looking for investors. Further to the investors ' money rent an office, pay the s/n and the usual.
If you find the crazy fan, that will work for the idea probably good design you will not leave or will he developed so long (crazy enthusiast also will have something there, so he will be the main place of work, and your project he will do in the evenings and weekends) that at the time of launch has become irrelevant.