Cotton:
Stink bugs are the main pest to be scouting for right now. Also be looking out for spider mites and whiteflies. These insects are important when deciding on an insecticide to spray. A good phone app to help with insecticide choice is the GA Cotton Insect Advisor App. Bacterial blight has been reported in some counties.
Peanuts:
The main diseases to be looking out for are white mold and peanut rust.
Soybeans:
Below is a guide to soybean scouting that has ways to identify caterpillars in soybeans and also thresholds for foliage and pod feeders.