1) well rotted manure, worm castings or mushroom compost. Lots if in red clay - MORE if in sand.
2) lime. You'll need a soil test to tell you exactly how much. Your county extension office will give you the supplies, test and give you results in a short time for a nominal fee. You need lime if you are in red clay.
3) gypsom is optional, and this year with the rain and looser soil I don't think you need it. It just helps incorporate compostables. You don't "need" it.
Perlite and vermiculite are used in square foot garden mixes. You don't "need" it either, and frankly I don't like them much in the soil.

Fertilizers: I like bone meal, fish fertilizer and/or blood meal to dig right into the soil. I also add kelp but these are also optional. You may prefer to use 10-10-10. It is up to you.

I mulch after planting and watering with cardboard and straw or home compost or leaf mold. Whatever I've got. I do not use wood chips or pinestraw in the veggie garden as they break down slowly and compost slowly - so when you turn soil in the fall they won't be broken down.

UGA has a great new sheet on Organic Gardening suggestions.I can't find their print file, but I did find this:

Here is a link that might be useful: UGA organic gardening

Hi girlgroupgirl,

Thank you so much - this is very helpful.

A couple of follow ups:

1. Where can I get well rotted manure around Atlanta, especially near Marietta/Roswell?
2. How much of the manure/compost do I need for a 10 ft by 10 ft patch? I'm assuming I'll till to a 2-3 feet depth to break up the clay.
3. Does the mix change for a flower patch instead of a vegetable patch?

Regards
Jim

Here is a link to Walter Reeves comments on amending soil. Helps with calculating how much you will need. You can purchase soil amendments, including fully composted manures at Lowes, Home Depot and Pikes Nursery. There are others, but these stores are all over the place. We have a small vegetable garden. It was easier for us to source and purchase the bagged amendments when we got started.

Here is a link that might be useful: Walter Reeves - amending soil.

It all depends on the condition of your navive soil. If it is purely
red clay, you will live a lot more yhan otherwise.
For a 100 sqr-ft garden, you will need a truck load of topsoil/compos.
So, buying by the bag is a costly proposition.

First, you have to check your soil, have it tested and it it is
half decen, go ahead till it or turn it mannually then add
amendmentss as needed.

JUST A SIMPLE MATH: ifyou add just a 6" layer over 100 sqr-ft
you will need ; 100ft x 0.5ft = 50 cubic feet = 5.5 cubic yards; That is about a truck load , I think

Isn't a cubic yard 27 cubic feet? 3x3x3

Sorry Mike, You are right.
I made a BIG error by a factor of 3.
You will need less than 2 cubic yard.

How you amend your soil depends upon what type of soil you have, its prior use, and whether it has ever been worked in terms of any prior amendments. Much of Atlanta has a very thin layer of topsoil, then a layer of clay and quartzite/gneiss rocks (as learned when building MARTA) Stone Mountain granite is beneath a lot of Atlanta), but almost certainly a hardpan layer a couple of feet down. Assuming clay, you need to affect the bonding of the soil particles that make it cling into the typical clayey mass. That is done with gypsum. Then you probably need to change the PH because most GA clay is acidic. Calcium carbonate limestone, as opposed to Dolomitic is best. Just read the label. The granulated at Lowes is Calcium Carbonate. Howerver, it takes a while for any lime to break down thoroughly to be used by the soil, which is why it is best to apply in the fall...though applying ASAP will help. You also need humus, i.e., organic matter. Remember that the breaking down of any new organics will use nitrogen, so the extra nitrogen of manures helps. There are plenty of sources of bulk compost such as Green Brothers ..where they have mushroom compost. Be wary of composts with sewage sludge due to heavy metals present. READ and ASK. In adding manures, it is best to get composted manures. If bagged, the cheap stuff is mostly wood chips and pine bark mulch. There are plenty of stables around Atlanta, but try for composted horse or whatever to lower the risk of e-coli. Be wary of most large scale compost makers as the components vary widely as do the processes. So, even without a soil test, you can be comfortable and safe with GA clay to add limestone, organic matter, and a bag of 10-10-10 well tilled before planting and given a week or more to settle in. Actually, the BEST plan is to deep till, add the above, till again, then develop raised beds framed or otherwise. For 10X10, get a copy of square foot gardening from the library or book store.