The first thing that you must do is get a mentor. This is the person that you go to with all of your questions, concerns and anxieties.
Find several business owners who are doing what you want to do and interview them. Ask them how they got started, and do they have any suggestions or warnings for you.Tell them to give it to you straight. Find out from these business owners if this idea will sustain you financially.
Assemble your team: accountant, lawyer, web designer, marketing, sales coach and support group(s), etc. You will need support groups to bounce ideas off of, and hear ideas that are working in other areas of business that might work in your area of business.
Attend conferences and trade shows in your area of interest. Attend meetings and conferences at your local Chamber, BNI, etc. Do not join any groups or organizations until you have visited them at least twice to get a feel for the type of people that are in the group.
Be ready for looooong hours of research and product/service preparation. It won't happen overnight....be patient.
Does your product/service sell itself? Can you sell? If you can't you will need a sales coach.
You must have a business plan, and someone to show you how to market your product/service.
Here are a few more items you might like to ponder:
1) There are some dreams you need to follow, and others you need to wake up from.
2) You only lose when you quit.
3) And the old Kenny Rogers advice:
Know when to hold 'em
Know when to fold 'em
Know when to walk away
And KNOW WHEN TO RUN!