You can see where your property tax dollars go by clicking here.
Property taxes are due each year on or before December 20th. If you choose to pay in two installments, the first half is due on or before December 20th with the second half due on or before June 20th of the following year. Subsequent billings may also be mailed in the event of a correction or late addition to the tax roll. If a structure is completed midyear or a personal property declaration is not received when due, a subsequent billing may result. See Idaho Code 63-903
Instructions are available here: