Here’s a 7 minute video from Youtuber Mbaier1234 which highlights how to format and then upload/use GIFT format questions to Moodle. For more information you might also check out http://docs.moodle.org/en/GIFT_format. Note that the video highlights the process on a Mac specifically.
Below is an example of two questions in the GIFT format. 
Enjoy!
Direct video link: http://www.youtube.com/watch?v=mRnMu6sIcJs
