A laundry line.
Wooden clothes pins.
A basket or bag to store clothespins in.
A laundry basket.
A shoe box or small container for socks
After you have washed your clothes, place the wet clothes in the laundry basket. They are heavy, so do this task on your own. Although, you can certainly explain to your child what you are doing. Then, take the basket outside. Your child can bring the basket/bag of clothespins. Either use a step stool, or a low-enough laundry line, so that your child can help you pin the clothes onto the line. Mother nature will take over from here! When the clothes are dry, reverse the process. You may bring the basket of clothes inside, while your child brings in the basket/bag of clothespins. Together you can fold the clothes. It is best to leave the napkins, washcloths, and socks to your child. They can certainly handle it!
For washcloths and napkins, have your child lay the napkin out in front of him. Smooth out all of the wrinkles. Bring the bottom to the top (folding the napkin in half). Then, fold one side to the other (folding the napkin in quarters).
For socks, the child can place one sock on top of the other. Both will match directions. He can smooth out the wrinkles. Then he can roll the socks up. When he finishes rolling each pair of socks, he can place them neatly in a shoe box or other small container, so they won't come unrolled. That box can be taken to the child's room, and the rolled socks can be transferred to their drawer.
Your child will certainly enjoy spending time with you in this way. Your dryer AND your electricity bill will get a break. And your clothes will smell GREAT!