A belt sander is a useful device that you can get in a handheld model that you have to control with two hands, or you can get it in a stationary style that you can leave on aw orkbench while you run items over it. It is a wide belt that is made of sandpaper that spins around on two wheels that are like a conveyor belt. They produce this long surface area where the sander is spinning, and you can push anything over it at any time to get it smoothed over or just cut down to the right size. You might be used to using sandpaper by hand, but you have to use something electric when you can.
The belt sander that you are using has a special trigger that you hold down when you are sanding, and you can turn it off at any time. You can hold it over something if you are sanding a large surface, or you can trim the edge of something that is very small. You might need to sand something like a tabletop, or you can run the sander over something like the rails on your deck or porch.
The belt sander forces you to use the trigger because you cannot keep it going unless you are holding down the trigger. You have to make sure that you have worn some kind of safety goggles, and you need to wear some kind of safety mask so that you do not get all the residual material in your eyes, nose and mouth. You could have wood or plastic material flying everywhere, and you have to have all your safety gear on you if you want to have the results that you need. Anything less than that is going to be very hard for you to handle because sanders are very powerful.
The tabletop versions have much larger sanders, and they usually come with variable settings that you can use to make sure you take off the right amount material when you are working. Other type of sanders can be found at http://www.sandersguru.com/ (Sanders Guru). There are a lot of people who want to have more control by running something over their sander slowly. You can actually sand curved things that you have run over the sander when it is sitting on a bench, but you need to wear protective gloves because you have to be sure that you cannot touch your hand to the sander. You can use the sander in both guises pretty easily, and you need to make sure that the power source is free and clear of any obstructions.
You are better off using the sander outside where you can get some ventilation, or you need to make sure that you have windows open so that the room does not fill with the material that you have sanded off this device. It is so much easier for you to smooth things over, and you can use these sanders in your workshop or your job to make sure that all the surfaces you work on are as smooth as possible.