From IFAS Here.
Sun-dried tomatoes can add a deep, tangy flavor to your cooking. You can buy them at the grocery store, but it’s more fun to grow your own. Plant plum or pear-shaped tomatoes since they’re best for drying.
Once they’re ripe, wash and dry the fruits and cut them lengthwise. Scoop out the seeds but leave the pulp. You can dry the tomatoes outdoors on racks in just a few days. Tent them with cheesecloth and be sure to bring them in each night. Another option is to sprinkle them with salt and put them in a 140 degree oven for six hours, leaving the door cracked so air can circulate.
Once fully dry, store your tomatoes in an air-tight bag in a cool, dark place. Putting them in the refrigerator or freezer can help them stay red.