Minecraft builder's guide: roofs, walls and arches
88 Oak Stairs, 55 Oak Planks and 11 Oak Slabs.

These planks are sawn from the common oak of forests and plains. Planks are the basic wooden building block: one log gives four, and they go into crafting tables, chests, tools and countless other recipes.
It is made with the Crafting Table from Oak Log (or another variant). It is mined with an axe. As fuel it burns for 15 seconds in a Furnace, enough to smelt 1.5 items.
Most recipes accept planks of any wood: a Crafting Table, a Chest, Sticks, wooden tools, a Barrel or a Bowl can be made from any mix. Recipes that keep the look of the wood, such as slabs, stairs, doors, fences, signs and boats, need planks of a single kind.
Overworld planks burn as fuel, each enough to smelt one and a half items, and they catch fire easily. Crimson and warped planks from the Nether never burn, which makes them the safe choice near lava.
Any of #oak_logs → 4 × Oak Planks
// Slots with several items cycle through every accepted option.
88 Oak Stairs, 55 Oak Planks and 11 Oak Slabs.
Oak Stairs, Cobblestone, Oak Planks
Fill the room with Spruce Planks and make every third row Dark Oak Planks.
At the Crafting Table: 1 × Oak Log (or another variant) gives 4 × Oak Planks. Mining the block drops it.
They are the basic wooden material for crafting tables, chests, tools, sticks and building. It is an ingredient in 50 recipes, made at the Crafting Table; for example Blue Bed, Bookshelf, Bowl, Brown Bed, Cartography Table and 42 more.
The fastest tool is the axe.
Yes. In a Furnace it burns for 15 seconds, enough to smelt 1.5 items.
Placed under a Note Block, Oak Planks gives the Double bass sound.
Yes: fire can spread to it and destroy it, and lava nearby can set it alight.