clothing stores     bakeries     grocery and meat stores.     If your business idea is on this list, it doesnt mean you should abandon it automatically. However, it should remind you to be extra critical and careful when preparing your plan. Ive known successful businesspeople in every category listed, just as I have known people who have failed in each of them.     Many people enter businesses they know little or nothing about. I did it once myself. I opened an automobile tune-up shop at a time when, seemingly, they couldnt miss. I knew a good deal about running a small business, had a personality well suited for it and could borrow enough money to begin. The end of what turned out to be a very sad story is that it took me two years and $30,000 to get rid of the business. Why? Because in my hurry to make a profit, I overlooked several crucial facts. The most important of these was that I knew virtually nothing about cars and I didnt really want to learn. Not only was I unable to roll up my sleeves and pitch in when it was needed, I didnt even know enough to properly hire and supervise mechanics. In short, I made a classic mistake-I started a business in a "hot" field because someone was foolish enough to lend me the money.     How can you apply my lesson to your situation? Lets say youve heard pasta shops make lots of money and you want to start one. First, if at all possible, get a job working in one, even if you work for free. Learn everything you can about every aspect of the business. After a few months, you should be an expert in every aspect of pasta making, from mixing eggs and flour, flattening the dough and slicing it into strips. Ask yourself whether you enjoy the work and whether you are good at it. If you answer "yes," go on to the second important question: Is the business a potential money maker? You should have a pretty good answer to this question after working in the field for a few months.     If youre unable to find employment in the pasta business, make a tour of delicatessens and shops that make their own pasta. Interview the owners. To get reliable answers, its best to do this in a different locale from the one in which you plan to locate. Small business owners are often quite willing to share their knowledge once they are sure you will not compete with them.     I remember reading a management philosophy that said that a good manager doesnt have to know every job, only how to get other people to do them. That approach may work well in a large corporation but for a small business, its dangerously naive. In short, dont start your small venture until you know it from the ground up. I mean this literally. If youre opening a print shop, you should be able to run the presses and do paste-up and layout, as well as keep a coherent set of books. If its your elegant little restaurant and the food isnt perfect, youre the one who either improves it in a hurry or goes broke. If you dont like getting your hands dirty, choose a clean business.