Instructions
Download a texture pack for Minecraft in the Texture Pack Central thread on the official Minecraft forums at minecraftforum.net.
Start Minecraft and click the "Mods and Texture Packs" option on the main Minecraft menu.
Click the "Open Texture Pack Folder" button on the Select Texture Pack screen to open the Minecraft texture packs folder in Windows Explorer.
Drag and drop the downloaded texture pack .zip file into the texture packs folder window that appears. The texture pack instantly appears on the Select Texture Pack screen.
Click to select the installed texture pack on the Select Texture Pack screen and click "Done."