It's important to know your utilities -- at least, the ones you're responsible for. Many complexes pay the water bill, but the power, gas and everything else is the renter's responsibility. Some apartments have a shared utility meter, which means that your utility cost is just a percentage of the overall bill. So, if you have a shared meter with the apartment next to you, the bill covers the utilities of both apartments and will most likely be split in half. That's great if the apartment is vacant, but your bill will skyrocket if you're sharing a meter with an energy-hog.
Fortunately, many complexes using shared meters offer budget plans where you're charged a flat monthly rate based on an estimate of the total annual utility costs. Budget plans ensure that your bill remains consistent over the course of the year, though you could still end up paying more than you would if you had your own meter. Make sure you discuss any concerns you have about your utilities with your landlord before you sign the lease.