The day I brought my turntables home was a truly happy day. I had saved money the old-fashioned way, by stashing away a little cash every week in a cookie jar. And I couldn't have been more eager to set up my decks and get to work. I thought the hardest part was over; after all, DJing looks like such a breeze from down there on the dance floor. But the most essential skill of DJing is more difficult than it seems: beat matching.
The most important thing to know about beat matching is this: learn how to do it. Many times, people are too eager to jump right into "chops" and skip the steps of learning basic skills. Hence, you get DJs who can scratch like crazy, but whose mixes are noisy and not smooth. Yuck. Remember, mixing is what sets you apart from the radio DJ. Although you may be playing a style that involves more cutting (like hip - hop or various kinds of non-computerized music) it is still crucial to learn the basics of mixing. You may never play two records at the same time, but the smooth transition from one to the next is the definitive reason why you're a DJ and not a jukebox. The entire point of matching the beat is to create a seamless set, each record weaving its way into the next, creating the perfect flow.
Beat matching is one of those riding-a-bike-like activities. It takes a while to get the knack, but once you get it, it's set. A good way to start learning is to buy two copies of the same record (if you're a hip - hop DJ, you'll be doing this anyway). Play them both at the zero pitch setting, but release them at different points, to hear how the beats will mesh when you're working with two different records. Begin with a simple beat; I think a straight - up house track is ideal. Learn how to count the measures. If you've never been trained in music, you may not know when an 8-bar phrase begins and ends, but listen. Listen for when the changes happen, when new elements appear and disappear. Learn to find the rhythm of the record.
The next thing to learn is discerning whether the incoming record needs to be faster or slower. This is a given for experienced DJs, but can be very challenging for a beginner. Many mixers have a feature that allows you to listen to both channels in the headphones at the same time. If you're in a club with a really bad monitor, this is a helpful feature, but when you're learning how to beat match, don't use it! First, many mixers you will use don't have this feature, so you have to learn how not to depend on it. Also, you'll find you probably prefer not to use it even when you have it. This tip is especially important for beginners, so you can keep straight in your head which record is in the house, and which is in your headphones. Then, practice speeding up or slowing down a record to match it to the other one. This is, of course, the frustrating part, but there is no short cut. You just have to keep trying and messing up (for months maybe) until you get it. And don't be ashamed to bring a DJ friend over to help you. After all, they once went through it too. When you do get it though, it will be like a "click" in your head, and all the frustration will suddenly give way to smooth sailing (and smooth mixing.)