Several years ago I spent some serious time working out a veggie-garden planting calendar for my yard. I have since discovered that the Old Farmers Almanac website has a feature that will create a planting schedule using US frost dates for gardens all over the US. A gardener just has to specify a location, and a schedule will appear!
The schedule includes dates for gardeners who also like to consider phases of the moon in their planting. I have checked the Old Farmers Almanac schedule for Kennesaw, and it is not too far off from the one I created for myself for most crops.
It shows later planting dates for potatoes (old-timers around here get their potatoes into the ground in March), and it has a very small window-of-opportunity for planting radishes. Some years I start sooner and others I end later. It also is only for the spring/early summer garden. However, a new gardener could do worse than to consider the planting dates suggested in the schedule.