Be sure to take the time to do good soil prep. Do it right the first time and forever after, gardening will be a pleasure.

My favorite re-seeders:
Vinca
Cleome
Chinese Forget Me Not
Larkspur: love the flower, but save some seed for insurance.
Melampodium
Gloriosa Daisy
browallia americana

My favorite are:
Verbena bonariensis
Malva Zebrina
Columbine
Melampodium

Love-in-a-Mist (Nigella)
California poppies

Echinacea 'Prairie Splendor' is a wonderful coneflower that I grow; it reseeds and I also collect the seed and scatter those at the same time that I pull the cones. It may take a year for the babies to show up, but in the 2nd year, they catch up quickly with mature plants. Perennial.

Celandine or Wood Poppy - (Stylophorum diphyllum). Spring blooming, scattered blooms throughout the summer-fall, until frost. Shade plant.
Georgia Aster (Aster georgianus or Symphyotrichum georgianum). Fall blooming - Honey bee magnet! Sunny locations.
Green and Gold (Chrysogonum virginianum, var.?). Another member of the Aster Family that forms a dense ground cover in partly shaded locations. Yellow flowers in late spring,
This is one of 2 varieties that also spreads by stolons, as well as seed. Some of the seed from my plants established a colony in a neighbors lawn, underneath a Red Maple tree. His attempt to eradicate it only invigorates it and it keeps spreading. Payback for his Japanese Honeysuckle & Privet, English Ivy & Chinese Wisteria, that I am forced to constantly battle!
All are native plants, so I don't have concerns about introducing a potentially invasive alien plant into the area.

Mom, you might want to slip over to the Carolina forum, a subset of the Southern Gardening Forum. Very active and we have 2 subforums for Conversations as well as Exchanges.
Zone 7/8 in Charlotte is on the southside close to SC and also in Union County near SC.

The vinca referred to is the annual flowering type, not the groundcover with the pretty lilac colored blooms(spring).
My best reseeders this year have been datura (highly toxic)and perennial ageratum that blooms the same time as my blackeyed susans. The BES are thugs,spreading wildly so they cover a good 6-10 square intersperced with the blueviolet frothy blooms of the ageratum and at the same height. Good for an English garden appearance but hard to keep inbounds in a less deep border.
The verbena B. comes up everywhere and grows thinly about 3-4' tall/spindly. The goldfinches adore the seedheads and watching them do their gymnastics to hold on to the swaying plant while feeding is fun to watch.
Gloriosa daisy is a very dependable reseeder. My first came down as seeds from Ct. in 1985 and have moved two more times. Excellent,long lasting cut flowers but they don't flower much beyond the first flush of blooms (now).

In your shady/part shady areas you can have great luck with coleus. Get the biggest plant you can find(bushy) and take cuttings and put them in plastic cups of water. In two weeks you'll have them all rooted (just plain water) and ready to put in the soil.

Are you somewhere where there are deer and/or rabbits?
'wonbyherwits' has great blogs and garden photos on how she deals with the critters and a spectacular landscape.

Dottie -- thanks for the compliments on my blog and garden. In fact, Southern Living Magazine's July issue is featuring my deer resistant garden.

I haven't seen it yet, but one of the other garden bloggers has, so I guess some folks have their magazine already.

Cameron

Here is a link that might be useful: my garden blog

Thanks for the head's up on the SL July issue, F.
We all appreciate the time you take to post here and share your photos.

Melampodium is very dependable, I agree.
Salvia coccinea (I think the common name is Scarlet Sage) is also very nice. It is an annual.

For plants that re-seed themselves, my all-time favorite has got to be Black-Eyed Susan flowers (Rudbeckia). We've had them re-seeding in one spot for probably ten years or more. Love 'em !! And the bright yellow flowers always seem to last for a good long while. We let them dry on the stem, then in the fall we shake any dry seed heads that are left, to help them re-seed for another year. Definitely a favorite! (We're located in Virginia, just north of Richmond.)