Generally speaking, there are two types of property legal descriptions: 1. subdivision description; and 2. metes and bounds. If your property is in a subdivision, the property description will locate the property within that subdivision and a subdivision plat map should also be available at the county (you only need the description for the deed, not the plat map). A metes and bounds description aligns your property based on measurements and landmarks. There is no preference between the two, so long as you have one that accurately describes your property.
The best place to find your property legal description is in the most recent deed recorded at the county--what should typically be the deed transferring the property to you.
If you are having trouble determining your property legal description, you should consult with an attorney in your jurisdiction.