To elaborate a bit on the bike thing - biking is extremely popular here, probably more so than anywhere in the world. It seems like all major and minor roads have bike lanes, and not just dinky little bike lanes that are basically just bicycles painted on the side of the street, but real, separated bike paths. You not only need to watch for cars when you cross the road, you need to watch for bikes. It can be a little disconcerting. The bikes are most often these huge heavy looking one speed black clunkers, frequently rusty. I was told it's because of the problem of theft. Also, gears are not as necessary because there's no hills at all.
I don't think I saw even one person wearing a helmet. Parents regularly have one or two kids on their bike, using rear seats, front seats, front carriers, or standing behind them on the hubs of the back wheel. And really, nobody wears a helmet! It really goes to show how culturally conditioned our extreme safety consciousness is. In the US, you would be thought of as a bad parent if you let your kids ride without helmets. Yet in Holland, an advanced, progressive, first world country if there ever was one, nobody does and it's just fine. It's all about perspective.
Non-motorized push scooters are extremely popular in Geneva, even for adults, for commuting. But you didn't see ANY scooters in Amsterdam. Just bikes.
People in Amsterdam were so friendly. Anyone that I asked for directions (in English, no less, I didn't even learn how to say "excuse me" in Dutch) answered cheerfully and extensively, in English, and they all ended with something along the lines of "have a great holiday in Amsterdam". Very impressive. Also we were on the tram one day, and a group of people of different ages that didn't seem like they started out knowing one another started chatting, and passed around a photo and had a good old time before they got off, separately. Okay, maybe I'm idealizing a bit, but people really seemed cheerful.
About garbage and litter in the street - I would say it's about the same as Geneva. The graffiti wasn't nearly as bad as in here in Geneva, though.
Geneva is nice enough, but after visiting Amsterdam, I was really wishing that our stay in Europe could have taken place there. Luckily I found that the weather in Amsterdam is about like Seattle - lots of rain and gloom. So I didn't feel quite so bad about it. Although the weather here in Geneva right now is nowhere near as nice and sunny as it was in March - that was apparently an anomaly.
So...what did we do? Lots of kid-focused stuff, really. Along with just walking around the canals, here's where we went:
—Artis - the zoo, we went here Easter Sunday and had to wait about 45 minutes to get in because it was so popular. The kids favorite part was a cool playground with a great slide. At the chimpanzee house we had a long talk with a lady who was very knowledgeable about chimps. The chimpanzees were supposed to all be sterilized, but one of them had a baby which unfortunately died a few days after it was born. The mother chimp apparently carried it around for a few days, but when we went there, it was laying on the floor. A little macabre.
—TunFun - a huge indoor playground that's actually a converted overpass, complete with concrete pillars supporting old highways, and old traffic lights. They had one slide which included a sheer drop of about 5 feet. Kenny, after some initial hesitation, ended up loving it and going on it dozens and dozens of times. Lots of trampolines, huge climbing area, ball pits, inflatables, etc.
We weren't planning on spending the day there, as a matter of fact we started to leave after a few hours, but after we'd packed up and walked out to the outdoors, we saw that it was pouring. So our plan to walk around the canals was not that enticing, and we decided to just stay there.
—Pancake Cruise - this was a fun evening activity, incorporating a cruise along the waterways (not the canals) and a Dutch pancake buffet. The boat had a little ball pit downstairs. Also we met a Moroccan woman with two boys who was very friendly, she's a real estate agent living in Amsterdam. Lots of cool-looking modern architecture along the waterfront.
—Nemo - a science and technology museum for kids. The kids liked the bubble building section the best.
—Canal cruise - the standard tourist canal cruise. Nice and relaxing, the kids played on our phones the entire time. Trying to get them to be interested in seeing the sights is a losing battle.
—The main library - interesting modern building with a good kids section. There was a fascinating exhibit called the Mouse Mansion made by artist and author Karina Shaapman. She wrote a book to go along with it (actually I guess she built the Mouse Mansion to go with the book!) We spent a long time there going through the book that is set in the mouse village, trying to find the room from each page.