First observation: the ship switches to Dutch time at about midnight, Dutch time is an hour ahead of UK time, and so you may be perturbed when the unsilenceable speaker in the cabin ceiling announces at a time you believe to be 5:30 that we will be landing in 90 minutes.
The event is behind the central station and thoroughly signposted from within the station.
The main area, with the tall ships you can visit, is the 'orange route'. This goes round two long sides and one short side of the old docks, it's a five-mile walk, and as far as I can tell at the end you have to retrace your footsteps five miles back to Amaterdam Central Station. Two of the more exciting attractions - the modern submarine Bruinvis and the current Dutch Navy flagship de Rutyers - are right at the far end. The submarine stops accepting visitors at 4pm, the flagship at 4:30; today I missed both.
You might be better off taking a tour of the ships from the water: you can buy a timed e-ticket from www.ntk.nl under 'sail', it's €20 for adults, €10 for children, €0 for small children. This tour puts you in the procession of ships that go round the dock: if you're walking, the walk goes clockwise and the procession goes clockwise and so often you'll keep up with the same processing boat for some time.
The first couple of visitable ships have long queues, the queues are much shorter for later ones. I would recommend the Ecuadorian ship Guayas, the enormous Staatsraad Lemkuh, and (on the second half of the circuit) the small but perfectly-formed Australian Young Endeavour, the unpronounceable Polish Dar Młodzieży, and right at the end the French Belem which used to be the private yacht of the Duke of Westminster and later of the Guinness dynasty. The Chilean Esmerelada is so near the start as to have a long queue, and has a slightly unreconstructed tone to it with "Victory or Death" and "la razon o la fuerza" mottos everywhere.
Bring loads of water: if you can, bring a picnic. There are loads of food and drink stalls, but the standard pricing is €2.50 for a small drink.