Look in the phone book under, "Marina". Tell them your boat length and they will quote you a price. The longer the boat, the more it cost.

I would think the fees would greatly depend on the location of the dock and the size of the boat you want to dock there.

You will have to find some marinas in your area and call them. There could be a waiting list too. they will charge per foot of boat. The boat will have to be insured as well and in safe condition, as in not about to sink. Cost on the West Coast can range from $15-$25 per foot. Manhattan is probably even more.

look on craigslist

New York/Manhattan is difficult to find slips for live-aboard boats, and you might not be able to do more than wash it at some marina's. But, a 40' slip near the tip of the island goes for $5100 a year, payable in advance. That's high, but an 2 bedroom apartment over looking the river is $2160 a month.