Going to Amsterdam, Prague, and Warsaw-any tips would be helpful

Have you bought your ticket to Anne Frank House?
If not you should do so today.

Here are some links that I hope will help you with Warsaw (you can easily see what the top sites are):
http://warsawtour.pl/en (Warsaw city guide)
http://warsawtour.pl/en/brochures (downloadable Warsaw brochures in PDF format)
http://freewalkingtour.com/ (various city walking tours)
https://www.inyourpocket.com/warsaw

You didn't mention Krakow specifically - I assume you wouldn't go to Auschwitz and skip Krakow? That would be a real shame because it's a wonderful city and doesn't get the huge crowds that Prague does. Here is some Krakow info. You didn't mention how you're traveling between these cities as they are quite far apart. I'm including the Polish bus and train links as well.

https://www.inyourpocket.com/krakow
http://rozklad-pkp.pl/en (train)
http://www.polrail.com/en (train)
http://www.polskibus.com/en/index.htm (bus)

In Amsterdam a visit to the Jewish Historical Museum, including the mighty Portuguese Synagogue, would be appropriate.
In Prague the New Jewish Cemetery in Olsany is an impressive reminder of the Jewish presence in the city.
Although somewhat commercialised a visit to the Kazimierz district in Kraków would also be fitting.

We assume you have read the appropriate guide books. Do you have question about trains, public transit, etc. The Red Light district in Amsterdam is vastly over rated, adds little and easily avoided.

The Schindler factory is in Krakow, and Auschwitz is about 90 minutes outside Krakow; neither one is anywhere near Warsaw. Are you actually going to Warsaw (which has its own Jewish, Nazi, and Holocaust related sights) or to Krakow?

Do get Rick's books for these places; he not only has information about what to see, but also detailed logistics about how to get there and get around (for instance, not just "there's a bus," but exactly where it stops).

In Prague you can do Jewish Quarter tour. Visit Cyril and Methods church on Resslova street, the last stand of SS Obergruppenfuehrer Reinhard Heydrich assassins. Maybe you have seen the movie Anthropoid. He was one of the authors of so called final solution, perhaps the most important author. I would recommend to visit concentration camp Terezin, it's one hour by bus from Prague. You will find all information about Prague and trip to Terezin and then some in Rick Steves book: Prague & the Czech Republic.

Auschwitz is near Krakow, not Warsaw. You can go on its website and make a reservation for a tour time, or there are many organized tours out of Krakow. I found that the tour guide at Auschwitz was exceptionally good. Krakow has a Jewish area with several synagogues and other sites. The Rick Steves book has details for a walking tour. Krakow is a wonderful city and well worth a couple of days there. Its older areas were not destroyed in the war, so you can see the real thing.

Warsaw has the POLIN museum, a terrific museum that explains the history of the Jewish people through 1000 years in Poland. They give guided tours, but you can go through it on your own. Be sure to allow plenty of time. My friend and I easily spent three hours there, and did not finish with the exhibits. I returned at another time and spent another two hours. They have a nice cafeteria where you can break up the day. You can also follow Rick Steves' walking tour of Jewish sites that begins next to the museum.

I also found the Warsaw Uprising Museum of interest. This is about the Polish uprising against the Nazis (not to be confused the Warsaw Ghetto Uprising). Warsaw has several large parks that are lovely if the weather is nice. The old town area was completely destroyed and then rebuilt after the war, and is a fun place to walk and eat (if a bit touristy!)

Prague has a Jewish quarter with several synagogues that can be visited. Again, the Rick Steves guide has a walking tour of this area. The central area of Prague is very walkable. You can see virtually all the sites by walking. Its public transportation is very good and easy to use (for instance to get up the hills!)

These cities are not that close together, depending on your transportation plans. Be sure to research this carefully.

Have a great time.

In A'dam, visit the Dutch Resistance Museum. Take a day trip from Prague to visit Terezin.

Plan carefully. You'll be in Europe over Easter weekend, with possible closures on Sunday and Monday too. It's a very busy time in Europe, so you should book trains and flights as soon as you can - and of course hotels. The Jewish Quarter sights are closed on Friday afternoons and Saturdays, so Sundays are typically crowded. They are also be closed on Jewish holidays so, if they are open on Easter Sunday, they would close early and will be closed on April 17-18 (last days of Passover) so expect it to be very crowded later in the week.