Farming is the act of planting seeds to grow various crops. These crops can be eaten for food or used in Cooking for further benefits.
Seeds can be found by harvesting bushes and thatch plants with a Parasaur, Triceratops, Metal Sickle, or rarely by hand then you can just plant them directly into dirt near a source of water to grow them. Once the plant is mature you can harvest it.
Irrigating is vital to a successful farm and in turn, your harvest. Using a Water Reservoir or Water Intake with a Water Tap will irrigate Dirt blocks up to a 3 block radius, on center.
Harvesting is fairly straightforward. Collecting your Crops by hand or with a Parasaur will yield more of the Crop whereas harvesting using a Triceratops or Metal Sickle will yield more seeds.