On the upper right of your screen (above the animation palette) you should see the file palette.  Use this palette to browse through the image folder's you'd created in step one to find the images you'll be using to assemble the initial key-frame.  Before you begin using the images you might want to take your time to give each image a custom pivot point. (images default to a top-left pivot point, and its often more convenient and leads to better final results to set pivot-points based on actual aspects of the image in question...for example, the image of an upper arm would scale and rotate more naturally around a pivot point set in the center of the shoulder).  To set a default pivot point for an image, double-click on that image in the file palette and a dialogue box will appear giving you the ability to set the pivot point. Once you've set the pivot point how you'd like, click OK.
Setting Default Pivot Points