How to Grow and Use Bananas, Coconuts and Pineapples
Bananas
The banana set is a full plant-and-wood chain. Grow it from Banana Shoots. The plant produces Banana Stem, Banana Leaves, and Banana Blossom. Fruit appears as Barely Ripe Banana Cluster, which ripens into Bananas you can harvest. Banana is the edible item. Use the Banana Stem, Banana Leaves, and Banana Blossom as plant blocks when building or farming the banana plant.
Coconuts
Coconut is the fruit item. Coconut Fronds are the leaf blocks of the coconut palm. The palm gives you a complete wood set: Coconut Log, Coconut Wood, and Coconut Planks. From Coconut Planks you craft the full family of building blocks: Coconut Stairs, Coconut Slab, Coconut Fence, Coconut Fence Gate, Coconut Door, Coconut Trapdoor, Coconut Button, Coconut Pressure Plate, Coconut Sign, Coconut Hanging Sign, and Coconut Shelf. You also get two boats: Coconut Boat and Coconut Boat with Chest.
Pineapples
Pineapples grow as blocks. Crownless Pineapple is the harvested fruit block, and Crownless Ripe Pineapple Block is the ripe version. Place and grow them the same way you handle the other fruit blocks.
Building With Coconut Wood
Because Coconut has Log, Wood, and Planks plus the full stairs/slab/fence/door/sign/shelf set, you can build an entire structure from one palm harvest. Craft Planks from Coconut Log or Coconut Wood first, then branch into the decorative blocks.