Ken Compton from Southern Home Inspection Services sent me interesting information on Wood Rot.

Question: How can I prevent wood rot on my window sills and trim?
Answer:
1. Keep the bushes and trees trimmed back from the house at least 18 inches.
2. The window sills need to be caulked and painted (check on the condition annually).
3. Remove the window screens from all the windows that you don't use for ventilation.  The reason is that the metal bottom section acts like a dam and water ponds on the window sills.  As the paint on the window sills deteriorates, water seeps into the sill and begins to rot.

The interesting thing is that wood rot occurs more quickly on NEWER homes than older homes.  The wood on older homes is truely stronger and more resistent to rot!