As a homeowner, your primary residence is eligible for what is known as the homestead exemption; a reduction in the property taxes you pay.

Further reductions in property tax are available to seniors 62 and up. The Fulton County Assessors' Homestead Exemption section of their website has more information about what the reductions are and the eligibility requirements. You must apply by April 1st; the site says the exemption must be applied for in person.  

You only need to apply once for the homestead exemption. Once granted, it is applied to your tax bill every year.

Property Tax Appeals

Each year, the Fulton County Board of Assessors sends out a tax assessment of your home that states what they think your home is worth on the fair market (that is, the amount a reasonable buyer would pay for your home).  This value is known as the fair market value.  This value is used in calculating the property taxes you owe.  

If you believe your property has been improperly valued by the county, you can appeal the assessment. Instructions and forms on how to do this are available on the Fulton County Board of Assessors Property Tax Appeals section of their website.