How can I travel to Paris?

[Tanter]

Hi friends,

I am an American and would love to travel to Paris. Does anyone know of a good tour group that goes there from the US? Is it difficult to get a visa to visit there? I've heard the people are extremely friendly and obviously the amount of history and culture there has got to be amazing. Has anyone traveled there and have tips on dress codes, safety, what to see, what to buy, what to eat, or anything else?
I'm looking for a shuttle from the airport Charles de Gaulle to the hotel, someone used the services of this company http://kiwitaxi.com , any recommendations?