Hi,
I think the best way to travel is by train. I think there is a train between Hamburg and Amsterdam and for sure there is a train from Holland to Paris. Last year I went with the train from Rotterdam to Paris, an ideal way to travel because it does n´t take that long. Book the train in advance, then you know how much it cost.
The train that you have to take is called the thalys.
This is the website: http://www.thalys.com/nl/en/
If I were you I should go for like 3 days to Amsterdam and the other 7 days to Paris.
Amsterdam is very nice but I think you have to see more in Paris so that takes longer.
In Amsterdam is nice to visit the Anne-frank house, madame tussauds, go with a sightseeing boat, see the Jordaan (typical amsterdamse neighborhood), Albert Cuijp market, Vondelpark and the many terraces on the squares (Rembrandtplein and Leidscheplein) in Amsterdam.
In Paris of course to see things like the Eiffel Tower, Louvre, Notre Dame, Arc de Triomphe, maybe also take a boat on the big river.
Hope this helps you, have a nice stay in Amsterdam & Paris!
OHannemarie