The first question you should ask yourself is WHY you want to start a business. The answer usually tends to be one of four choices; Wealth, Fame, Independence, or Community.
Most people will be driven by all four of those choices to a point, but one will really stand out. For me it was always Fame. I wanted to be "known" in my community as a smart, savvy business person. I wanted to be recognized and appreciated for my skills. I wanted people to know that I could "make it" and "do it".
Wealth and independence are the most common choices. First, with wealth, there is nothing to be ashamed of when wanting to make tons of money. Profit is not a four letter word! Independence is also a common choice but I often found that independence is the hardest to achieve. Successful business owners usually work twice as long and twice as hard as the average 9 to 5 worker. Sure, you "have the freedom to spend more time with your family" and all those others catchy sales lines you see on websites, but the fact is that if you are working 17 hours a day (which is common when going out on your own), there are only 8 hours left. In those 8 hours you have the "freedom" to do whatever you want.
Community or charity is the least common reason for starting a business. This usually comes much later and is often chosen by business owners who already have a few successful companies.
The great thing about finding what drives you is that if you are honest with yourself, the others will come together in the end. If you are not honest with yourself, most likely your business will not be a success and you won't have to worry about anything accept finding a job.
The second question you need to ask yourself is what you are good at...AND BE HONEST! Most likely you are not a marketer. Most likely you lied to yourself about that. And most likely, if you are still looking for the success that you want, that is why you aren't there yet.
You need to concentrate on the skills that you possess and do them to the best of your ability. Then you need to find others to work with you to fill in the blanks.
If you are not honest with yourself with this assessment, failure is almost guaranteed.