There are numerous lists all over the Internet. Some are strange and silly, but this post by Steve Pavlina is a good one, "10 Stupid Mistakes Made by the Newly Self-Employed." What I like is how he has told his own story. Here are a few excerpts from his lengthy but worthy post - make sure you visit especially if you plan on starting a business soon.

Having been a non-employee for about 14 years now, I've made my share of stupid business mistakes. I've also coached a number of people to start their own businesses, and I've seen many of them make similar mistakes. This advice is geared towards small business owners, particularly people who are just starting (or about to start) their own business.

1. Selling to the wrong people.
2. Spending too much money.
3. Spending too little money.
4. Putting on a fake front.
5. Assuming a signed contract will be honored.
6. Going against your intuition.
7. Being too formal.
8. Sacrificing your personality quirks.
9. Failing to focus on value creation.
10. Failing to optimize.

It takes significant effort to build a successful business, but it's also a tremendous growth experience. I know many people who have quit their jobs to run their own businesses. Many of them didn't do as well as they'd hoped, but I don't know any that regretted taking the plunge. There's simply no substitue for holding the reins of your own destiny.