In a one gallon jar, put:

1 onion sliced or coarsely chopped
2 c. white vinegar
1/2 c. sugar
1/4 c. salt (not iodized)
Several sprigs of dill or
1 tbsp. dill seed (herb)

Slice cucumbers lengthwise and put into gallon jar with above ingredients. Fill jar with cold water to the top. Shake to dissolve sugar and salt. Ready to eat in 12 hours. Keep in refrigerator.