If you run your car into a ditch, don't panic. Four men in a four wheel drive pickup with a 12 pack of beer and a tow chain will be along shortly. Don't try to help them, just stay out of their way. This is what they live for.
Don't be surprised to find movie rentals and bait in the same store.
Remember: "Ya'll" is singular, "All ya'll" is plural, and "All y'alls'" is plural possessive.
Get used to hearing, "Y'all ain't from around here, are u?"
Don't be worried at not understanding what people are saying: they can't understand you either.
Be advised that "He needed killin'" is a valid defense here.
And, if you hear a Southerner exclaim, "Hey, y'all, watch this!" stay out of the way, as these are likely the last words he'll ever say.