The archive will extract to a folder called _NOOBS_v1_3_1_ or similar, it is the contents of the folder that should be copied to the SD card, not the folder itself.
The SD card should be a new SD card, or one that has just been formatted as FAT. If it's a new SD card, its ready to go. If you are recycling an SD card, reformat it so you get the most space available with the official SD association formatting software
Simply copy the contents of the downloaded and extracted NOOBS folder onto the SD card. This will create an SD card from which the Raspberry Pi can boot.
When you open up the SD card in your Finder/Windows/Linux computer you should see the following in the 'base' directory, they shouldn't be in a folder!
