WASD keys to walk. Space to jump. Shift to sneak. Ctrl to sprint. Left-click to mine/attack. Right-click to use item/place block. E to open inventory. Q to drop held item. F to swap item to offhand. 1-9 to select hotbar. Esc to pause. Arrow keys to look around.
Originally by Mojang Studios. Yes, I know how to make all this work. Trust me.