If you want to make a progress image (gif) like the one I have below), here are the steps.
Your best bet to learn how to do it is to save mine to your hard drive. Then open it in whatever you use (photoshop? I use Gimp). You will notice it is saved as a 'gif' file (the suffix after the file name and the period) and it has layers.
You need to scan your image as you go. Try to scan it in exactly the same position on your scanner, but if you are photographing it, you can always adjust it later. Since I used and 8x10 board, it's easy to use the scanner and then I don't have to move them to match the previous layer later, but if you have to move them, that's easy.
Also, reduce them to the same size.
Then, have your first wip image on the bottom layer. Open up all the other progress images and copy each one, one by one. Paste it into a new layer making certain you have your progress in the correct order (I'm assuming a basic understanding of how to use an image editing program - if you have no understanding, the online helps are easy to use).
Do this til you've finished and then you'll have to save the layers with extra script. I use 0.8 of a second on my wip images and 3 seconds on my final one so people can see that longer. The script is
new layer#1 (800ms) (replace)
(#2, #3 etc etc for the other layers)
The final layer (on the top) will look something like
new layer#7 (3000ms) (replace)
Now, when you save it, (remember I'm using Gimp so it might be slightly different in Photoshop) you save it as primaballerina.gif
Mine then comes up with a dialog box which asks me either to 'flatten image' or 'save as animation'. Obviously I save as animation. Another box comes up where I have it set to loop forever.
I hope that helps.