First, download the framework from MTS, then unzip the file.
Next click on the Framework file and then remove the Mods folder from within it.
Cut and paste the Mods folder into Documents>Electronic Arts> Sims 3 folder.
Now click on the Mods folder
and the inside should look like this:
Ignore the other two files: the Packages folder is where all cc is placed.
Clicking on the Packages, it will look like this:
Now you can place your zip and rar file cc in here. It helps if you make labeled folders to keep your cc organized, like this:
and this:
Now delete all the cache files in Documents> Electronic Arts>The Sims 3. Note that you may not have all the cache files I have listed, or you may some cache files I don't have listed - that's okay. The cache files that look like pieces of paper are the only ones you need to delete. Also,unless you have SimPE installed like I do, your caches will not have SimPE written on them - they will just be blank.
Launch your game and if the intro splash screen is skipped automacally, then you know Mods are working properly! That's due to this file that MTS put in there that skips the intro so you can tell if everything's working or not.