Hi,
Paris is a beautiful place and it is best enjoyed by foot. The local train service is excellent and you can go to almost any place using it . All you need to do is have a plan.
This website gives all the information you need to visit Paris:
Paris Places of Interest and Tourist Information
Some of the must see places are Notre Dame, Triomphe De Arc, Eiffel Tower, Louvre museum - before going to Louvre, either read up Da Vinci code or buy the museum information book inside the museum an then go around looking, it will throw a lot of light and you will enjoy. I spent almost a ay in Louvre - if you are an art buff and if you have time, don't miss Versailles. Here you get to visit the palace of Louis XVI and Mary Antinnotte (
Paris Places of Interest and Tourist Information). French revolution i very intereting and you get see the actual rooms where it all happened. If you are interested, Normandy is another place to visit (
Battle of Normandy - Wikipedia, the free encyclopedia).
It is very easy to travel by train and the only trouble we had was sometimes with food (esp if you are vegetarian) and water - it is quite expensive. We just carried water around along with a some snacks and fruits. That said, we travelled with a one year old and had a fantastic time.
My sincere advise, look up the places, see the distances and plan your trip. Everything else is easy. Hope it helps.
All of you out there going on a holiday to Paris, have a great time.