Gas leaks are hard to find as they evaporate so fast. If you have a gas leak you will smell it and on a fuel injected car the pressure is so high that they tend to spray large amounts of gas. To find the source of an oil leak it is best to first clean the area thouroughly with brake cleaner and paper towels. Then run it for a while and you will be able to trace where the leak is coming from. You also have to consider that oil gets blown backwards from wind as the car moves.
The timing belt should be changed at 60,000 miles. So, if it has never been done you should do so now as it will destroy the engine if it fails.