I was in property management for years. You've got a couple of problems. The first is that you signed a one year lease. Without seeing a copy I can't say for sure, but all the leases I used held the tenant responsible for the rent through their lease period regardless of notice they gave. The only exception is if I was able to re-rent the apartment. Then they only had to pay until the new tenant moved in.
You should be able to find a landlord/tenants rights department through the local board of housing. They can help you with advice. Frankly, I'd try to cut a deal with him, but you can risk going to court if you want to.
I'd be really careful about posting signs or whatever around town saying he is a crappy landlord. That can get you in even more trouble.
Seriously, contact a mediator or tenant rights board. You should find one in the yellow pages. That's the best place for you to start, not on a board of pornographers.
