Step 1 - Download the resource pack you want - you can download texture packs from trusted sources like texturespack.com
Setp 2 - Copy the file you downloaded
Step 3 - Press ⊞ Win + R. A window titled "Run" should appear
Step 4 - In the textbox inside the "Run" window, type "%appdata%" and click "Ok"

Step 5 - In the folder that just appeared, open the ".minecraft" folder

Step 6 - In the ".minecraft" folder, open the "resourcepacks" folder

Step 7 - Paste the resource pack in this folder
Step 8 - Open Minecraft, select "Options", then "Resource Packs", select your resource pack and select "done"


You can skip 4,5, and 6 if you want to, you have to type this in the "Run" window: %appdata%/.minecraft/resourcepacks

Optional Method:

Step 1 - Launch Minecraft and navigate to the 'Resource Packs' menu.

Step 2 - Look for the 'open resource pack folder' button and click on it to open a folder (if nothing shows up, try exiting full-screen mode).
Step 3 - Put the zip file into this folder and you're ready to go.




Enjoy!