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. You can use the quick-set icons at the top right of the dialogue to set instantly and accurately set the default pivot point of the currently selected image to any corner, center, or the middle of any of its sides. Once you've set the pivot point how you'd like, click OK.
Setting Default Pivot Points
You might end up with several images that use the same size, especially in order for image swapping purposes.  In this case, don’t worry, you won’t have to set the same custom default  pivot point ot them all manually.  Just set the custom default pivot point to one of them, then click the “Copy Default Pivots” button Under the “Currently Equipped Tools” section of the Palette, then multiselect all the images you want to have the same default pivot point and click the “Paste Default Pivots” button.