You've got a lot of work to do...
To start, go to your Secretary of State Department and get some information from them on what would best suit your company to register under. Many startups register as LLCs. If you don't know where this is in your state, you can find it and everything else you need to register on your state's government website.
Create a feasibility plan and a business plan for your company (this part sucks...) that you can show potential investors. For starters, perform a SWOT analysis and analyze your market very concisely. Your business plan will be your company's bible, for lack of a better description. An elevator pitch is another tool that startups can use to quickly catch the attention of potential investors.
Most of your startup income will be out of your own pocket unless your business really has a high feasibility in today's economy. If that's the case, you could probably land some great investors to get you started, although this is pretty rare.
As a startup, you might not have the funds necessary to seek professional advice from a lawyer, accountant, or entrepreneur, but you can find pretty much any information you need on the internet nowadays. I recommend you utilize as much free information as possible and educate yourself on being an entrepreneur.
There's much more that goes into creating a solid startup company, but I'm sure you can find all this information and more on your own. I hope this helps you out a little bit. (I graduated with a bachelors in entrepreneurial management in case you were wondering if I'm legit.)
Feel free to contact me if you want more info, but I can't guarantee I'll be able to reply too often... I'm not on NS much anymore. Being an entrepreneur keeps you super busy ;)