Add the sex and torture museum to the list. That city is Disney Land for adults.....
If you stay at a hostel, either don't take valuables with you on the trip or take them with you when you go for the day. I had a PSP when I went, along with other items, left them in the locker locked up under a pile of clothes in there. When I came back, some soldier on leave from Iraq broke the lock open and stole what I had inside.
Seriously, I did the canal tour. Anne Frank house. Go to the museum district, there are a few to choose from. Lots of great restaurants too.
Don't forget about the Heineken brewery tour! The Anne Frank house is a must (be ready for a long line though.. at least 1+ hour wait when I was there) and the Van Gogh museum is amazing. A midnight stroll down the red light district is a must to be considered a true visit to Amsterdam.
Got drugged and robbed there once. Don't want that to happen to you? Don't get drunk and accept drinks from strangers like I did when I was wet behind the ears!
The nicest museum is the newly renovated and recently re-opened Rijksmuseum. All the Dutch masters from the 17th century are there. It's right next to the van Gogh museum, which seems to be the most popular with tourists.