I paid my property taxes today (they are due by the end of April). You can pay by mail but I always go to the office of the Receiver of Taxes and pay in person. The April payment is the town and county portion of the property tax. The school tax portion is paid separately in two equal installments due in September and January.
Property taxes in Westchester can be onerous but mine aren't too bad. In part this is because my condo isn't worth a lot by local standards. Also condos are assessed at a lower rate than single family houses. There is some justification for this because the condo association is responsible for some expenses (like plowing the streets in the complex) which would otherwise be the responsibility of the town. Finally the STAR program (which reduces school taxes for owner occupied housing) has a greater percentage effect on people already paying less in taxes as it tends to reduce everyone's taxes by a fixed amount.