I can't install mods and other custom content in sims 3

nics1023 Posts 3 Registration date Sunday May 25, 2014 Status Member Last seen May 27, 2014 - May 25, 2014 at 05:42 PM
It was my first time downloading mod for my sims 3, i have found a site like www.modthesims.info and nraas, i even watched a tutorial, i did everything they said but when i opened my game nothing was changed, can someone help me fix his?