There are numerous ways to get out the airport at CDG, but I like the Air France bus (stops at Porte Maillot and Etoile). You can follow the signs to the bus. Just inside the terminal from where you catch the bus is an ATM.

In Venice, the water taxis are fun, fast and expensive. They're sleek polished wood motorboats and they get you to town in about 20 minutes. When I was there last year it was about $100 US each way though. The ferries are far cheaper and take close to an hour to get to town.