I can't remember the name, but if you find Madam Tussaud's, it's right around the corner from there, near a supermarket. It's just off the main square, at any rate.
DO SEE: Amsterdam history museum, Jewish museum (if you're interested in that), one of the art galleries (I saw the Van Gogh museum, which loses for featuring ONLY Van Gogh artwork, so I'd skip that one).
SKIP: Anne Frankjhuis (rip-off), boat ride (you can see the same thing on foot, at your own pace).
Mostly it's fun to just walk around town. You're going in Summer, I went in Winter, but you should still have a good time. Just don't go into any booths with blondes inside them. And beware of where you consume brownies and muffins.
HINT: The coffee shops are really easy to tell apart from the 'coffee shops', so you should be fine
And I assume you'll be staying in one of the houseboats along the canal? That sounds really cool. I stayed in a dingy little hostel in the Red Light District, not as bad a location (or room) as you might have thought. Close to everything, and noise levels were generally much lower than would be expected.
Oh, and if you're single, the girls are gorgeous, and VERY approachable.
Can't wait to go back there.