The most important selection you can make at your wedding is choosing the right DJ.
Now there are a few questions you must ask yourself when choosing a DJ such as do I want a laid back reception or a very outgoing one? Another question is what type of equipment must the DJ have? And lastly what is your budget for a DJ? There are many DJ's out there that don't understand exactly what their job is.
I have to play music and watch people dance right? WRONG! The DJ is not there just to provide music and equipment, he is there to make sure everything is in order from the introduction, toast, dinner, and first dances.
He must also be interactive and timely so your guests will not get bored and leave! Now how important is the equipment? I would put an importance of about 1/3 on what equipment the DJ uses.
Pay attention to how much the DJ knows about his system such as what is the RMS wattage on his speakers and amps? Also pay attention to what brands he is using, If he starts listing brands such as pyramid, Gemini, technical pro, client beware! Another questions is how important is lighting? Here's a quick view would you rather be dancing in a well lit room where everything can be seen, or under a bunch of light to distract the guests.
Lighting sets the mood, A good DJ will have full control over his light show, to where he can set the perfect coloring for your first dances, and set the party atmosphere for later.
I hope this article helps in your selection of a DJ!