This year your property taxes will be due on the 1st of April, 2006. The bill will be for the year 2006-2007. There will also be arrears on the bill if you did not pay past taxes.
The town council is not always up-to-date in their files so if you know you have paid a past amount that is not shown on your bill don't freak out, simply send a copy of the receipt and submit payment for the amount you know you owe.
As the town council is a little slow on changing the new ownership of properties bills are often in the previous owners name for years after the fact unless the new owner makes a big point of having the records changed.
Normally if you bought a property the title isn't changed into the new owners name unless proof of property taxes paid up-to-date is provided. However, as a new owner it is your responsibility to ensure the taxes are paid up to date prior to you paying the old owner off, otherwise you might well end up with back taxes owed on the property.
Of course the system is subject to human error.
Typically you can have a few years of arrears under your belt before the town council sues you for payment. If you don't pay they will eventually have the right to auction off your land to pay the tax bill.