This step is where some addons require some extra attention.
Open up this folder and you will find the Addons folder. Now that you have opened the World of Warcraft folder, you should see a folder named Interface. (Default is C:) Next, open the Program Files folder, then locate your World of Warcraft folder. From there, open the hard disk that you have WoW installed on. For PC users, you'll need to open the My Computer folder from your Start Menu. For Mac users, you will need to open a new Finder window, open up your Applications folder, then open your World of Warcraft folder. Hopefully if you know enough to change the defaults, you won't need this guide. I' ll detail how this is done for a default installation, using the default file structure. You'll need to locate your World of Warcraft folder.
At this stage, you've got some unzipped folders sitting in front of you, it's time to find them a home.