What goes on in Amsterdam during New Year's Eve?

Amsterdam, in fact all cities, most towns and many villages in the Netherlands, are having fireworks going all day and night, officially only till 3 AM but it is not unknown to hear them going from 27-12 to 3-1 almost continually.
At midnight almost every body will fire off fireworks, there will also be a main show like in other cities in the world. Everybody will likely go out on the street, enjoy the fireworks and then go on to a club or some such, or back home to celebrate with friends.

There is a strong tradition in the Netherlands to go to Amsterdam for all main feast days, to find parties and get into clubs. But this night there are many 'closed doors' which means that you have to get a ticket well in advance or will not be allowed in.

There have been years with 'open' open air concerts and events, but those have basically stopped due to safety considerations. If there are still out of doors events, they will sell or give away tickets but without a ticket you will not get in.

I would suggest you to google Amsterdam oudejaarsavond 2016 (or new years eve but that will give you fewer results) and see if you can find tickets for events or clubs. Add your prefered style of music and you will likely find many.
I have not been to Amsterdam on NYE (nor on any of the main events) but friends who have been are very positive. (It is not the events, it is me.) But if you can not get tickets for clubs or events, I would not bother coming, as far as I have heard, not much change getting into places without tickets.