holy moly ok, first, buy this immediately and read the whole damn thing:
Amazon.com: The Startup Owner's Manual: The Step-By-Step Guide for Building a Great Company (9780984999309): Steve Blank, Bob Dorf: Books
next, if anyone tells you to write a business plan, tell them "dchuk told me never to talk to you again, sorry" and walk away. This is the internet, so, 1) you can't predict a damn thing about what's gonna happen a year from now and 2) you sure as hell can't predict growth/revenue/etc. So don't even try, it's honestly a waste. Again, study the book I linked to.
You have a few options in terms of "getting it built". you can learn to code, which is technically the "cheapest" and not as hard as people say as long as you have the right resources to work from. If you want to learn to code, I recommend two resources:
[Free]
Ruby on Rails Tutorial: Learn Rails by Example book and screencasts by Michael Hartl
[Free if you know how to google]
Amazon.com: Rails 3 in Action (9781935182276): Ryan Bigg, Yehuda Katz: Books
(NO ONE START A LANGUAGE WAR THATS NOT THE POINT OF THIS REPLY)
Study those books. Type every single character in by hand. Learn it inside and out. Live on Ramen and work 12 hours a day through one of those books and you'll have a very solid foundation for building your own frankenbeast startup.
You could also either hire someone or bring on a technical cofounder. I don't recommend the latter, as we programmers will quickly grow to resent the imbalance of work being done initially and it most of the time doesn't end well. So hire someone is my advice. But you need money. You can try pitching VCs and getting some cash, but every single VC is going to expect a functional demo at the very least unless you're somehow related to Peter Thiel or your last name rhymes with shuckerzerg. So, back to learning how to code. Coding isn't hard, it's just a mindset. It's a powerful thing to know how to do. Don't worry if your code is janky, just build something.
Finally, hit me up on skype: iamdchuk and tell me some details about what you're thinking about. I promise that I'm not interested in taking any ideas, I'll just steer you in the right direction with a lot of this shit. The actual coding of a product is not as bad as people make it out to be, but building something you can safely deploy to the world and market effectively requires a shit ton more steps that most posers don't talk about.