It sounds like you just need to start from the beginning. :) That means start writing a business plan. A business plan will help you figure out what you don't know and what you need to know. For example... a business plan should have a section on your competition - which means you should know who you're competing with; a business plan should have a financial sections - which means you need to do some research on how much your start up costs will be, your pricing, etc.
A few other good resources to get your started:
- check out your local Small Business Development Center
- there are a bazillion books on Business Plans out there available at any book store or library
- I also have a questionnaire available on my blog to help folks figure out what they need to know when they're just starting.
It's available here.
Hope this helps!
-Adeena