First and foremost, you need to look for signs of damage. Generally, wherever there is damage, there is going to be a leak. Look for leakages if any. You can spot this problem if you notice brown spots on the ceiling of your house. Locating the leak points will help you spot the location of the damage.
Check the damaged part by examining every single aspect. Climb up a ladder and check it thoroughly. A visual inspection often helps. Just walk around to notice these small defects.
Check the shingles for cracks, punctures or tears. Check the gutters that are attached to the roofing of your house. Hail storms can easily puncture the shingles. Look for small indentations or large holes. This can be easily identified by noticing the change of color in the shingles. Punctures will appear like dark dots or rips.
Check if any damage has been caused by nearby trees. Look for cracks and tears in the shingles. The branches of the trees are capable of lifting the shingles or ripping them apart when they sway back and forth due to gusty winds.
Check the elbow-plating. Damage to this part may look like a dent or as if the plating has been pulled away from the top or the wall of your house.
You can try the above inspection if the roofing is at a reasonable and reachable height. If it is too high, it is better to seek the help of a professional contractor so that you do not end in any kind of mishap.
Avoid trying to make temporary repair instead of finding a permanent solution as this can add to your woes instead of lessening it. Employing a good contractor is the ideal thing to do in such scenarios.
While looking for a good contractor make sure that you get one who is listed in yellow pages. It can also be help to ask for a recommendation from your neighbors, relatives or friends. Do not employ anyone who is not a roofing expert as any shabby work will cost you more in the long run.