So you seed started and you're ready to plant but there is one more step, hardening off. Seedlings are tender and have been in a controlled environment since germination. Hardening off slowly introduces the seedlings to changing temperatures and levels of sunlight and wind which can help build strength.
Hardening off is done over a weeks span. A week prior to hardening off stop watering your plants. Choose a spot outside that will be protected from harsh wind and direct sunlight.
Mid to late afternoon place your seedlings outside for an hour or two. Each day leave your plants out for an hour or two longer (based off weather conditions. be careful in the colder months), slowly introducing them to more sunlight and less shelter. After a few days lengthen the nighttime hardening as well. Lightly water plants as needed.
Now you're ready to plant! make sure to give the seedlings a nice soak right before planting and water them in after planting as well.