The priority when a roof leak is detected is to minimize damage as much and as quickly as possible. Here is a list of actions to take as soon as you see water coming through the ceiling. 

• Move the items that are under the leak – This may seem like an obvious step, but it will minimize the damage to furniture and other valuables. Get electronics out of the way first as they can suffer damage with minimal exposure to water. This step can also determine the pieces that can't be moved and should be covered with a plastic tarp if one is available.
• Shut down the circuit breaker if outlets are being exposed to water – Water and electricity are not a great combination, so if a leak is directing water to outlets, appliances, or other hard-wired electrical devices, shut down the circuits on the electrical panel to prevent the delivery of electricity to these affected areas.
• Put a bucket or a basin in place to collect water – In this situation bigger is better, so find the biggest receptacle you can find as long as you can carry it when it's full. If the leak is coming from a high ceiling, it may splash out of the basin, requiring more clean up and/or incurring more damage. The easiest solution in this situation is to drape a towel over the basin to catch and absorb droplets and minimize splashing.
• Inspect a painted ceiling closely – Bubbling ceiling paint can be an indication of accumulating water from a leak, which can cause a big mess if it is released at one time. To drain these accumulations slowly, take a pin to penetrate a side of the bubble as poking a hole at the lowest point may cause the blistered paint to rupture.
• Try to find the location of the leak – If you have an attic, the leak is probably dripping there first and then coming through a low point in the ceiling. After containing the leak in the living area of the home, get up in the attic to see where water is dripping and accumulating. While it's unlikely that you'll be able to do anything about the leak, you may be able to set up another bucket or basin as a first line of defense to minimize damage to the ceiling.

After taking these steps, it's time to call the local roofing contractor. As it often happens, if your roof is leaking, especially after a long dry spell, there is a good chance that other homes in the area are experiencing the same thing. Making the call to your roofing contractor quickly can get you closer to the front of the line and ensure that your roof is repaired sooner rather than later.