Once you pick up the side quest from the farmer in Kakariko village you will need to find all of the chickens that are scattered around the village. Most of them are quite easy to find. Some of them might be a little more tricky and one, in particular, might get you when it comes to the plum trees.
When you find a cuckoo, you can pick it up above your head and run around with it. Throw it into the fence near the chicken hut for it to count. If you jump off a ledge whilee holding a chicken, Link will glide down to the ground below. This will make it quick and easy for you to get back to the chicken pen once you pick one up from a higher location in the village.
It is much quicker to look at the video below than to read a text description. The video below will show you the location of every cuckoo hidden in Kakariko village.