One of our favorite yearly events...between the music, the food, and the Purina Dog/Frisbee event, this is not to be missed.
Parking, like all events of this nature, can be a bear. Try to carpool AND take MARTA, though, and you'll be fine.
Also, try to stay all day, if you can. The musical acts come and go, and it's fun to sit and peoplewatch.
And, even though it's called the Dogwood Festival, dogs are not welcome at the event, unless they are competing. I always see one or two, but generally, speaking, leave Fido at home.