Your hotel is in Amsterdam North, you need to go on a ferry to get to the center, which is at the other side of the IJ. The ferries leave from the central station.
Here is a ferry map.
http://www.gvb.nl/reizigers/plattegronden/Pages/verenkaart.aspx
I believe you need the red one. It's a 15 minutes ride.
Here is the schedule for your ferry.
http://www.gvb.nl/reizigers/soortenvervoer/Documents/ndsmwerfveer.pdf
As you can see it doesn't go all night. On the map you see a green ferry, that one goes all night.
Here is the schedule.
http://www.gvb.nl/reizigers/soortenvervoer/Documents/buiksloterwegveer.pdf
So if you want to go home later then the last red ferry you need a bike to go to the hotel from where the green ferry stops or you need to take a night bus.
There are night buses that go to Amsterdam north, here is the map.
http://www.gvb.nl/reizigers/plattegronden/Pages/nachtlijnen.aspx
I think you need the grey one (the 363), it leaves from central station.
Here is the schedule for all the night buses.
http://www.gvb.nl/reizigers/toegankelijkov/Documents/nachtbus-dec09web.pdf
In the night bus you have to pay in cash, I don't really know how much it is, 3 euro something I believe. So don't pay with a 50 euro bill because the driver will not like that.
There is a bridge over the water but it's far away from the center and I guess if would take an hour or so the get to the botel (by bike)
The botel used to be in another place, which was a 2 minutes walk from the central station but it had to move due to construction works there or something.