If you are using a single DJ or a band, always have a plan for how to cover the entertainment should they cancel. If you are going through a larger DJ company they will typically have additional DJ's on staff that can fill in, but a single DJ may not have that option.
Ask if the DJ or band has ever played at the venue you are using for your reception. This is particularly important if they have a lot of equipment or need special power outlets or other items to set up with. If not, the DJ or band should go in advance to make sure they have enough space to perform.
Typically you will be required to put down a deposit for either a band or a DJ. If your wedding falls on a holiday be prepared to pay more for services and put down a higher deposit. The deposit amount should clearly be indicated on the contract.
