Firstly you go to a website that offers texture packs like planet minecraft
Secondly you download the texture pack
Thirdly put it somewhere you will remember it e.g. Desktop
Fourthly run minecraft and click on options
Fifthly click texture packs and then click open texture pack folder
Lastly drag the folder in the texture pack folder and then close texture pack folder,then your texture pack will apear on the texture packs list click the texture pack you want click done go onto your world and enjoy the texture pack you downloaded :D.
Also when you make a texture pack of your own this same rule applys

Thanks for reading rummax