A starter chimney is a great investment. Don't worry if you don't have one but I recommend that you buy one. You can light and have perfectly good barbecue without a starter chimney, see Lighting to find out how. A starter chimney will make lighting a barbecue quicker and give you a few minutes to check that your barbecue grill is clear of ash.
Another use for a starter chimney is to give you a measurement of charcoal which will probably lead to you using less charcoal for a barbecue than you would otherwise have used. Since it is my preference to use a starter chimney you'll find reference to the quantity of charcoal in relation to the starter chimney's capacity.
I use a Weber starter chimney. The Weber starter chimney is larger than most other starter chimneys and does appear to be off a better build quality than most. The handle is perhaps better and more heat resitant than others. If you keep your starter chimney somewhere dry it is sure to give you many years of good service.
Usually, unless you begin to Low and Slow cook or if you are going to be cooking a lot of food over a longer period of time, it will only be necessary to light up the starter chimney once. When and if you have the need for more hot charcoal you can start more charcoal and add it when it is hot. This is particularly useful as it will ensure a continuity in cooking and reduce the exposure of smoke to your food. Some smoke is given off during the intial stages of lighting charcoal and this is normal. It is a good idea to have an idea how long 1/2 and a whole chimney of charcoal takes to reach the optimum cooking stage, that is grey ash just forming over all surfaces. My reckoning for charcoal briquettes is between 15-25 minutes depending how loaded the chimney is. By knowing this you can plan ahead for both when you're barbecue will be ready to cook on or to give you time to make sure that your fire doesn't burn out before you had more hot charcoal.
To see how to light charcoal in a starter chimney take a look at BBQ Lighting and watch a video.